build(frontend): sweep every stylesheet, not index.css by name

The hook fires on frontend/**/*.{ts,css} while the script read one hardcoded path, so a second stylesheet would have been silently unswept while the hook still went green over it. There is only index.css today, which is exactly when this is cheap to fix. Watched catching a planted nested rule in a second file.

.gitignore

@@ -88,3 +88,8 @@ build/android/overlay.json
 # Written by @semantic-release/changelog purely to carry the release notes
 # into scripts/gitea-release.sh; the release page is the changelog.
 .release-notes.md
+
+# Agent session log: local scratch, not repo memory (that is CLAUDE.md
+# and .planning/). Written by the scheduled backlog runs.
+.pi/journal.md
+.pi/schedule-prompts.json

.pi/prompts/next-issue.md

@@ -0,0 +1,142 @@
+---
+description: Take on the next actionable backlog issue end to end, and stop
+---
+Take on exactly one issue from the YellowJacket backlog, end to end, and stop.
+
+Repo: yonlu/yellowjacket at https://git.ljones.me — API base
+https://git.ljones.me/api/v1/repos/yonlu/yellowjacket, auth with
+`-H "Authorization: token $GITEA_TOKEN"`. Default branch is `main`.
+
+## 1. Orient before you pick
+
+Read, in this order: `CLAUDE.md` (the architecture and the reasons behind
+it), `.pi/journal.md` (what happened last), `.planning/NOTES.md` (what was
+already considered and rejected), and `.planning/plans/active/`. Do not skip
+this because the issue looks small — most of this codebase's traps are
+written down in exactly one of those four places, and the ones that bite are
+the ones you didn't read.
+
+## 2. Pick the issue
+
+List open issues. Choose the single highest-value one that is *actionable
+right now*:
+
+- Order by `Priority/Critical` → `High` → `Medium` → `Low`. Within a tier,
+  prefer `Reviewed/Confirmed`, then `Kind/Bug` over `Kind/Enhancement` over
+  `Kind/Feature`.
+- Consult issue #73 (the roadmap) — if it sequences the candidates, that
+  ordering wins over the label ordering.
+- **Skip** anything labelled `Status/Blocked`, `Status/In Progress`,
+  `Status/Abandoned`, `Reviewed/Won't Fix`, `Reviewed/Duplicate`,
+  `Reviewed/Invalid`, or already carrying an open PR.
+- **Skip anything someone else is already on.** The label is not the only
+  claim, because a concurrent session may not have applied it — several pi
+  sessions run against this repo from separate worktrees under
+  `~/.paseo/worktrees/`. Run `git ls-remote --heads origin` and skip any
+  issue whose number or slug matches an existing branch (`60-…`,
+  `fix/<slug>`). A duplicated fix costs more than a skipped issue.
+- **Skip** anything that cannot be verified without hardware you do not
+  have: physical-device Android behaviour (audio output, on-device file
+  writes, real gesture input). A browser at 424px is not a phone — see the
+  Chrome 113 section of `CLAUDE.md`.
+- **Skip** intermittent-failure issues unless you can reproduce the failure
+  on demand within a few minutes. Chasing a 1-in-3 flake is an unbounded
+  task and does not belong in a scheduled run.
+- If nothing qualifies, say so, do nothing, and stop. An empty run is a
+  correct outcome.
+
+## 3. Claim it
+
+Add `Status/In Progress` to the issue and comment that you are picking it
+up. Then branch:
+
+```
+git fetch origin && git checkout -b <type>/<short-slug> origin/main
+```
+
+`<type>` matches the issue's `Kind` (`fix/`, `feat/`, `refactor/`, `test/`,
+`docs/`, `ci/`). Branch from `origin/main`, never by checking out `main`
+itself — this repo is worked from several git worktrees at once and `main`
+is checked out in one of them, so `git checkout main` fails outright.
+
+## 4. Do the work
+
+Fix the issue that was reported and nothing else. Match the surrounding
+code's style. Follow the constraints in `CLAUDE.md` rather than reasoning
+from first principles — where it explains why something is shaped the way it
+is, that shape is load-bearing and there is usually a test pinning it.
+
+**Anything else you discover becomes a new issue, not a bigger diff.** File
+it with the right `Area/`, `Kind/`, `Priority/` labels, describe the
+symptom before the theory, and link it from your PR. Scope creep is the
+failure mode this instruction exists to prevent.
+
+If the work turns out to be materially larger than the issue implied, stop:
+comment on the issue with what you found and what it would actually take,
+remove `Status/In Progress`, push nothing, and end the run.
+
+## 5. Verify — the right tier, not the cheapest one
+
+Run `make generate` if you touched `.sql` or `.templ`, and `make bindings`
+if you changed a bound Go signature. Then run what the change actually
+demands:
+
+- Go change → `make lint` and `make test` (both cover all three build
+  configurations).
+- Frontend component or store → `make ui-test`.
+- User-visible flow → `make e2e` against `make dev-headless`. **Check the
+  port first**: `ss -ltn | grep 34115`. If it is occupied, another worktree
+  is already running the app — do not start a second one and do not run
+  `make e2e`. Attaching to someone else's build produces a green result
+  about code that is not yours, which is worse than no result. Either
+  choose an issue that does not need this tier, or stop and say why.
+- Anything cosmetic or layout-related → look at a screenshot. Several bugs
+  in this repo's history were invisible to every assertion and obvious in an
+  image.
+
+A tier you skipped is a claim you did not check. If a tier fails for reasons
+unrelated to your change, say so explicitly rather than quietly moving on.
+
+## 6. Keep the documentation true
+
+If you changed structure, behaviour, or a constraint, update `CLAUDE.md` in
+the same commit. That file is this project's memory; a change that leaves it
+describing the old shape is worse than no change. Append a short entry to
+`.pi/journal.md` covering what you did, what you verified, and what you left
+open.
+
+## 7. Commit and open the PR
+
+Conventional Commits, imperative subject, ≤72 chars, scope optional. The
+body explains *why*. Push the branch — never push to `main`, never
+force-push.
+
+Open the PR:
+
+```
+curl -sS -X POST \
+  -H "Authorization: token $GITEA_TOKEN" \
+  -H "Content-Type: application/json" \
+  https://git.ljones.me/api/v1/repos/yonlu/yellowjacket/pulls \
+  -d '{"head":"<branch>","base":"main","title":"<subject>","body":"<body>"}'
+```
+
+The body states: what the issue was, what you changed and why, **which
+verification tiers you ran and their results**, anything you deliberately
+did not do, and `Closes #<n>`.
+
+Then wait for CI (`ci.yml`, jobs `check` and `e2e`) and report the result on
+the PR. If it fails, read the log — `gitea_ci`'s `job_logs` 404s on this
+Gitea build, so use
+`GET /api/v1/repos/yonlu/yellowjacket/actions/runs/<run>/jobs` for per-step
+status and `GET /api/v1/repos/yonlu/yellowjacket/actions/jobs/<id>/logs` for
+the log — and fix it. Two consecutive failed CI runs on the same cause: stop,
+comment what you know on the PR, and leave it for a human.
+
+**Do not merge.** Comment on the issue linking the PR, leave
+`Status/In Progress` on, and end the run.
+
+## Finally
+
+Report in three lines: which issue you took, what state it is in
+(PR open / CI green / stopped and why), and any issues you filed.

.pi/skills/yellowjacket-dev/SKILL.md

@@ -130,7 +130,13 @@ reference, because you need them *before* the failure, not after.
   what you otherwise get is `Property 'scroll' does not exist on type
   'CSSResult'` pointing at a line of prose, or every test in the suite
   failing to import. It went in after the trap cost a fourth session in
-  which its own warning had been read twice.
+  which its own warning had been read twice. **The same command carries
+  a second CSS check**: a nested rule whose selector starts with an
+  element name (`audio-player { … }` rather than `& audio-player { … }`)
+  is silently dropped by the device's Chrome 113 and by nothing else, so
+  every tier you can run renders it correctly. Run it after touching
+  `index.css` or any `css` literal; a rule directly inside a top-level
+  `@media` is not nested and is not flagged.
 - **A failing CI job's log is reachable even when `gitea_ci job_logs`
   says it is not.** That endpoint 404s on this Gitea build. The REST
   API answers, with the `GITEA_TOKEN` already in the environment:

.planning/NOTES.md

@@ -4487,3 +4487,301 @@ is not orphaned" and "a docked column is not in the stack" are both
 vacuously true of a build that pushes no entry at all. Reverting the
 source and re-running is what established which were which, and the
 file says so in its header rather than implying all nine reproduce.
+
+## The phone's transport, and three things that only a screenshot or a stash could see (measured 2026-08-21)
+
+#59 and #56 were done as one PR — argued on #73 first — because they are
+the same row of pixels: one removes controls from the phone's bar and
+the other enlarges what is left, and both are one property on
+`player-controls`. Measured at 424x439 before:
+
+| control | before | after |
+|---|---|---|
+| bar: shuffle / prev / play / next / repeat | 33x21 each | prev/next 44, play 56, shuffle+repeat moved |
+| bar: favourite | **18x14** | 44x44 |
+| bar: queue button | 33x29 | gone (#59) |
+| Now Playing: all five | 33x21 each | 44, play 64 |
+| desktop bar: all five | 33x21 | **33x21** |
+
+Four things cost a cycle each and are worth keeping.
+
+**A `<button>` does not inherit its font from its parent.** The UA
+stylesheet gives it one, so `font-size: inherit` on a button is a
+*change*, not a no-op: it took every desktop control from 33x21 to
+36x24 by moving them from 13.3px to the shell's 16px. Nothing failed.
+The only way it surfaced was measuring the baseline by stashing the file
+and re-running.
+
+**And the pixel it was first pinned with was the wrong assertion.** The
+spec asserted the literal `'33x21'`, measured in Chromium — and WebKit
+draws the same button **36x24**, so it failed in CI on a build where
+nothing was wrong. A button's box comes from the UA stylesheet when the
+author sets nothing, and what each UA sets is its own business. What
+must not happen is that *we* set something, so that is what it asserts
+now: `min-width` and `min-height` compute to `0px`, and the font-size
+still equals that of a bare `<button>` probed in the same page. That
+form catches the `font-size: inherit` regression in either engine —
+checked by re-introducing it — and it is the same "assert the
+mechanism" move `queue-as-a-screen.spec.ts` makes about containment.
+
+It is also the second time in two sessions that **CI's WebKit was the
+only tier that could see something**, which is the argument for checking
+that step ran rather than trusting the run's conclusion.
+
+**A rule at the bottom of `index.css` still loses to a nested rule
+above it.** The phone block is last on purpose because a media query
+adds no specificity — but `#queue-button` is written *nested* inside
+`.bottom-bar`, so it builds to a descendant selector one class more
+specific, and a bare `#queue-button { display: none }` in the phone
+block did nothing at all. Silently: the button simply stayed. Nesting
+adds specificity the source does not show.
+
+**Removing a control moved the question of how you reach what is left,
+and ten specs were quietly asserting the old answer.** Hiding the bar's
+queue button failed ten tests in four files about the back stack and
+about layout, every one of which opened the queue by clicking
+`#queue-button`. `openTheQueue` in `e2e/support/fixtures.ts` is the
+route *this viewport* offers, and the fix was to stop hard-coding one.
+
+**And the route it takes did not exist in the state that matters.**
+`now-playing` renders two branches, and the no-track one had no
+`.expand` button — so with nothing loaded there was no way to Now
+Playing, and once the queue button left the bar the queue was
+unreachable outright. The queue is persisted across restarts, so this
+is a state the app launches into, not a corner. It first appeared as a
+*flake* (#168: the long-lived e2e app meant whether a track was loaded
+depended on which spec ran first), which is worth remembering — a leak
+made a deterministic bug look like a race.
+
+## Now Playing does not fit a 439px screen, and #56 makes that visible (measured 2026-08-21)
+
+Two separate things, and only the first is a defect.
+
+**The art overflowed its own box and drew over the header and the
+title.** It is `width: min(100%, 60vh); aspect-ratio: 1`, so its height
+is derived from its width and bounded by nothing — 60vh bounds the
+*viewport*, not the room left over, and those differ by all the chrome
+above and below. `max-height: 100%` is the fix and shipped with #56.
+Pre-existing: screenshotted on `main`. **Found by reading a screenshot,
+which is the only tier that can see it** — nothing fails, the shell does
+not overflow, and every control is still hittable.
+
+**With that fixed, the art is a 39px sliver**, because the transport is
+now 172px of a 439px screen. That is a consequence of #56 rather than a
+fault in it, and it is filed as #172 with the per-element budget. #64
+(no in-app volume on Android) is ~30px of pure gain there and #51 is the
+umbrella; folding shuffle and repeat back onto the primary row was
+considered and rejected — it buys 52px, leaves the art at 91px, and
+costs a third arrangement of the same five buttons.
+
+## The volume is not ours on Android, and the predicate could not be a width (measured 2026-08-21)
+
+#64 asked for the in-app volume control to be absent on Android. Its
+first Finding said `volume-control` "already stands down at narrow
+widths", which was true of one of its two copies and is why the issue
+had been read as nearly done. The bar's copy goes by width; the
+full-screen view's copy was deliberately kept, with a comment saying a
+slider does belong there.
+
+**The crux was platform versus width, and three options were on the
+issue.** What settled it is that the *backend* half of the same issue —
+pin the level at 1.0 — makes a width rule wrong on the platform the
+issue is about: an Android tablet at >=600px gets the bottom bar, and
+the bar's slider would then move a level that is pinned. That is a
+control that cannot act, which `library-status-indicator` already
+settled is worse than none. The same rule is wrong the other way below
+600px, where a narrow desktop window has no hardware keys.
+
+So the frontend asks the player — `SystemOwnsVolume` — and the answer
+is right at every width in both mount points. **The predicate is named
+after the capability rather than the platform**, which is what makes it
+testable: only `platformOwnsVolume` is behind a build tag, in two files
+that declare nothing else, and everything else is decided against a
+field a Go test sets either way. `frontend/test/components/
+volume-ownership.test.ts` stubs the binding and so exercises the
+*Android* rendering on an ordinary Linux runner; both of its tests were
+confirmed to fail on the build before the change.
+
+**Measured at 424x439, by flipping `platformOwnsVolume` to true in the
+`!android` file and rebuilding** — the real binding, the real store, the
+real component, everything except the tag:
+
+| element | before | after |
+|---|---|---|
+| header | 48 | 48 |
+| **album art** | **39** | **68** |
+| title / artist / album | 63 | 63 |
+| transport (seek + controls + volume) | **172** | **143** |
+| — seek bar | 19 | 19 |
+| — player-controls | 116 | 116 |
+| — volume-control | 21 | **0** |
+
+29px, which is the 21px control plus the 8px flex gap it stops drawing:
+a gap is only painted between boxes, so `:host([hidden])` costs the
+transport nothing rather than leaving a hole. That is #172's "~30px of
+pure gain" confirmed, and the art is 74% larger. It is still the
+second-smallest thing on the screen, which is #51's evidence.
+
+Three smaller things worth keeping.
+
+**`:host([hidden])` has to be written down.** The UA's `[hidden]`
+rule is `display: none`, but `volume-control`'s own `:host` sets
+`display: inline-flex` and outranks it — so setting `hidden` alone
+hides nothing. Same family as the nested-`#queue-button` specificity
+trap from the session before.
+
+**Rendering `nothing` and hiding the host are two different
+assertions**, and the component test makes both: an empty shadow root
+is what stops a by-role or positional query finding a button that
+cannot act, and `hidden` is what stops the host occupying space. Either
+alone passes on a build that gets the other wrong.
+
+**The bar's centring survives the control going away.** #23's outer
+columns are the same `min()` expression rather than content-sized, so
+at 900px with the volume gone the bar's centre, `audio-player`'s centre
+and `player-controls`' centre are all 450 — checked, because "the
+transport is centred with a slider bolted to one side" is the fault
+that rule exists for and removing the slider is the obvious way to
+re-break it.
+
+**What no tier here can check**: the constant itself, and ducking
+against a real audio-focus change. The first is a source sweep
+(`TestPlatformVolumeOwnershipIsDeclaredOncePerPlatform`), the second is
+`TestSystemVolumeStillDucks` against the arithmetic. Neither is a
+device, and no device was attached.
+
+### The device answered three of the four (measured 2026-08-21, TLP301 / Android 14 / SDK 34 / arm64, Chrome 113 at 424x439)
+
+A Light Phone III was attached after the PR was opened, so what that PR
+listed as unverifiable was re-checked rather than left as a caveat.
+
+**The whole chain resolves on the device.** `__yj.call("player.Player.
+SystemOwnsVolume", [])` answers `true` — build tag, `platformOwnsVolume`,
+`Player.systemVolume` and the generated binding, end to end. That is the
+one thing the source sweep only approximates, and it took a real arm64
+device because nothing else here compiles the `android` file at all.
+(`GOOS=android GOARCH=arm64 CGO_ENABLED=1 go build ./backend/...` with
+the NDK's clang compiles it in ~40 s and is worth running first; it
+catches a type error but not a wrong constant.)
+
+**The control is absent in both mount points**, on the real engine:
+`.bottom-bar volume-control` is `hidden` with an empty shadow root, and
+so is `now-playing-view`'s. Measured on the device, transport **143px**,
+which is the figure the desktop-headless "after" predicted exactly. The
+art is 75px there rather than 68 because the fixture's `.names` block is
+one line shorter, not because anything differs.
+
+**Nothing persists a level nobody chose, and this is the measurement
+that took some care.** The default (50) surviving proves nothing, since
+50 is also what a fresh row holds. So: force-stop, pull `yj.db`, set
+`player_state.volume = 37`, push it back through
+`run-as … dd` (a `cp` from `/sdcard` is refused — the app sandbox
+cannot read it), relaunch, and drive a queue change to make the row be
+rewritten. Reading it back **the WAL has to be pulled with it** — the
+main file still showed the old `last_track_path` and reads as a write
+that never happened. With `yj.db-wal` beside it: `last_track_path` is
+the new track, so `saveState` ran, and `volume` is still **37**.
+
+**The duck cannot be verified on this device, and now for a stated
+reason rather than for want of hardware.** `WailsForegroundService`
+builds its `AudioFocusRequest` without `setWillPauseWhenDucked` on
+API >= 26, so the framework attenuates the stream itself and never
+delivers `AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK`. The device's own log
+says so: `MediaFocusControl: requestAudioFocus() … AA=USAGE_MEDIA/
+CONTENT_TYPE_MUSIC … req=1 flags=0x0` — no
+`AUDIOFOCUS_FLAG_PAUSES_ON_DUCKABLE_LOSS`. **`minSdk` is 21**, so the
+Go-side duck is not dead code; it is reachable on Android 5.0 to 7.1
+and on nothing newer. Any future "verify ducking on a device" needs one
+of those, and asking for a modern phone will not do it.
+
+Two smaller things from the same session.
+
+**A fresh install downloads the real catalog, and it is 209px of the
+screen while it does.** `YJ_CORE_INDEX_URL` is stubbed in
+`dev-headless.sh` and in CI but is real on a device, so the first
+measurement taken was of a screen with `job-band` on it and the art at
+**0px**. That is not a defect and not #172 — it is the environment.
+`explore.Service.StopIndexBuild` and a relaunch is the clean state.
+
+**The first-run wizard does not dismiss when a library appears by a
+route other than its own** (#175) — it was still up, full-screen and
+intercepting pointer events, after `AddLibrary` succeeded through the
+binding, and was gone after a relaunch. Filed.
+
+## The context menu was clipped on the device, and the fix needed four measurements nothing here could make (measured 2026-08-21, TLP301 / Chrome 113 / 424x439)
+
+#60 had been diagnosed from the Web Awesome source and was right. What
+the device added was the numbers, and three things the reading had not
+reached.
+
+**The clip, reproduced before any code was written.** Long-press on the
+lowest visible track row at 424x439:
+
+| | |
+|---|---|
+| viewport | 424x439 |
+| `.main-panel` | 0 to **318**, computed `contain: content` |
+| menu panel | 191 to **401**, 210px tall |
+| clipped away | **83px, three of seven items** |
+| `wa-popup` computed position | `fixed` |
+| `HTMLElement.prototype.hasOwnProperty('popover')` | **false** |
+| row height | **29px** (against a 44px floor and a 48px ask) |
+
+A screenshot shows the menu sliced off flush with the mini player's top
+edge. Both halves of the diagnosis are therefore measured, not inferred.
+
+**"A dialog escapes containment" was the premise, and it was untested.**
+Every dialog in this app is mounted in `index.html`, *outside*
+`.main-panel` — so nothing here was evidence about a dialog opened from
+inside a view, which is what this change needed. A probe `<dialog>`
+appended to `track-list`'s shadow root and `showModal()`n paints to
+y=439, over the mini player and the tab bar. A top-layer element's
+containing block is the viewport, paint-contained ancestor or not.
+Checking that first cost ten minutes and would have cost a rebuild.
+
+**The UA stylesheet is the thing that makes a naive sheet look wrong.**
+That same probe came out **354px wide on a 424px screen**, centred,
+because a native `<dialog>` carries `max-width: calc(100% - 6px - 2em)`
+and `margin: auto`. `max-width: none` and explicit margins are four
+declarations that are pure undoing.
+
+**A retry loop cannot win against a steal that happens later.**
+`MenuKeyboard` focuses the first item and returns as soon as it lands;
+`wa-dialog` then focuses `[autofocus]` or *itself* on the frame after
+`showModal()`, and it cannot see our first item to prefer it — the
+panel is slotted through `menu-surface`, so the dialog's own
+`querySelector` stops at the `<slot>`. Measured: the sheet opened with
+`document.activeElement` on the `<dialog>` and every arrow key went
+nowhere. Lengthening the retry budget does not help, because the first
+attempt *succeeds*. The surface announcing `menu-shown` after
+`wa-after-show`, and the keyboard re-asserting, is the fix.
+
+**The submenu was made worse before it was made better, and only a
+measurement caught it.** `#playlist-submenu` is a
+`placement="right-start"` flyout anchored to its row. Making the menu a
+full-width sheet moved that anchor to x=0, so the flip put the playlist
+picker at **x −182 to 0 — entirely off-screen**, and "Add to Playlist"
+led nowhere at all. Before the change the anchor row started at x≈245
+and the same flip landed it on screen. It is a `menu-surface` too now
+and stacks as a second sheet. Two lessons: a change that moves an
+anchor changes every flip decision downstream of it, and *the scope I
+declared on the issue was wrong* — I had said I would measure the
+submenu and file it, and the measurement said fix it.
+
+**And the sweep found two call sites the conversion missed.** Twelve
+were converted by hand; `menu-surface.test.ts` reads every source file
+and fails on a `<wa-popup>` outside a three-file allowlist, which
+immediately named `queue-panel`'s add-to-playlist popup (a real menu,
+converted) and `now-playing`'s cover preview (a hover affordance in the
+bottom bar — allowlisted, since a touch device never opens it and
+nothing clips it). A thirteenth menu written as a bare popup would pass
+every tier here and be clipped on the device, which is precisely why
+the guard is a source sweep rather than a rendered assertion.
+
+**What no tier here can see remains the clip itself.** This runner's
+Chromium and CI's WebKit both have the Popover API, so the popup is
+top-layered and correct and a "not clipped" assertion passes on the
+broken build. The specs assert the *mechanism* — that the surface is a
+native `<dialog>` at phone width — which is the same move
+`queue-as-a-screen.spec.ts` makes about containment and for the same
+reason.

CLAUDE.md

@@ -646,7 +646,11 @@ rather than renaming them.
   level rather than writing through to the volume, so it cannot
   accumulate and nothing persists or emits a level the user did not
   choose — and it only ever fires below API 26, where the framework
-  does not already duck the app itself.
+  does not already duck the app itself. On that platform "the user's
+  level" is a constant, since #64 pins it at maximum and refuses every
+  way to move it; the duck is the one thing that still may, and it
+  works unchanged because it was always an offset applied *to* that
+  level rather than a write of it.
 - `system` — OS-specific paths (XDG on Linux, `%LOCALAPPDATA%` on Windows).
 - `explore` — Catalog search and browse over `explore_index`. See below.
   Its **shelves** (`shelves.go`) are the page Explore shows before
@@ -1363,8 +1367,17 @@ against the real components:
   `wa-dropdown-item` sets its `role` in its *own* first update, so a
   `[role^="menuitem"]` query at `updateComplete` finds nothing — which
   reads exactly like a menu that opened and refused to take focus.
-- **`focus()` on a popup that has not positioned itself is a silent
-  no-op**, so the first focus is retried across a few frames.
+- **`focus()` on a surface that has not shown itself is a silent
+  no-op**, so the first focus is retried on a *time* budget rather
+  than a frame count — the thing being waited for is another
+  component's animation. And a retry is not enough on its own for the
+  sheet below: `wa-dialog` focuses `[autofocus]` or *itself* on the
+  frame after `showModal()`, and it cannot see the first menu item to
+  prefer it, because the panel is slotted through `menu-surface` and
+  the dialog's own `querySelector` stops at the `<slot>`. The first
+  attempt therefore *succeeds* and is then overwritten, which no
+  amount of waiting fixes — so the surface announces `menu-shown` when
+  it has settled and `MenuKeyboard.refocus()` re-asserts.
 - **Focus is only taken back if the menu had it.** A click elsewhere
   closes the menu too, and pulling focus to the row the user
   right-clicked a moment ago is worse than leaving it.
@@ -1372,6 +1385,69 @@ against the real components:
   moving focus without setting it leaves the highlight on whichever
   item the mouse last touched.
 
+**And a menu is drawn where it fits: a popup on a desktop, a bottom
+sheet on a phone** (#60). `components/menu-surface/` is that one
+decision. The host renders the panel it always rendered and slots it
+into whichever surface is up, so `ContextMenuController` still drives
+`.active` and `.anchor` as though it were talking to a `wa-popup`, and
+fourteen call sites changed one tag name each and nothing else.
+
+**It is a correctness fix, not a taste one, and the failure was
+measured on the device rather than inferred.** Chrome 113 has no
+Popover API, so `wa-popup` takes its own documented fallback and
+positions with `strategy: "fixed"`; `.main-panel` carries
+`contain: layout style paint`, and paint containment *clips* fixed
+descendants. On the reference device the main panel spans 0-318 of a
+439px viewport while the open menu spanned 191-401 — three of its seven
+items cut off, with no way to reach them. `showModal()` is Chrome 37
+and uses the real top layer, so a dialog is immune by construction.
+
+Six things about it are load-bearing.
+
+**"Dialogs are fine" needed checking, because every other dialog in
+this app is mounted in `index.html`** — outside `.main-panel` — so it
+was not evidence about one opened from inside a view. A probe dialog
+appended to `track-list`'s shadow root paints to y=439, over the mini
+player and the tab bar, with the contained ancestor still in place. A
+top-layer element's containing block is the viewport, contained
+ancestor or not.
+
+**The sheet has to un-do the UA stylesheet.** A native `<dialog>`
+carries `max-width: calc(100% - 6px - 2em)` and `margin: auto`, which
+drew a 354px panel floating in the middle of a 424px screen.
+`max-width: none` plus explicit margins is what makes it a sheet.
+
+**The row sizing lives in `contextMenuStyles`, not in the component.**
+The panel is the *host's* light DOM — it stays in the host's shadow
+root, so only the host's stylesheet can reach it. `menu-surface` puts
+`data-sheet` on the panel and that shared stylesheet does the rest,
+which is how fourteen menus went from 29px rows to 48px ones in one
+edit.
+
+**A dismissal has to travel back.** `wa-dialog` closes itself on
+Escape, which would leave the controller believing the menu is open —
+and the failure mode is not a stuck sheet but the *next* long-press
+doing nothing, which reads as the gesture breaking. `menu-dismiss` is
+that signal; the three surfaces that do not use `ContextMenuController`
+bind it themselves.
+
+**The playlist submenu is a sheet too, and it had to be.** It is a
+`placement="right-start"` flyout, and making the menu full-width moved
+its anchor — measured at x −182 to 0, entirely off-screen, so "Add to
+Playlist" led nowhere. It stacks as a second sheet over the first,
+which is also why `menu-shown` does not re-assert focus while the
+submenu is open.
+
+**And which call sites exist is swept, not remembered.** A thirteenth
+menu written as a bare `<wa-popup>` works perfectly in every tier here
+and is clipped on the device, so `menu-surface.test.ts` reads the
+source and fails on one outside a three-file allowlist —
+`menu-surface` itself, `job-indicator` (in `.top-bar`, which no
+ancestor contains — the contrast that proved the diagnosis on #62) and
+`now-playing`'s cover preview (a hover affordance, which a touch device
+never opens). **The sweep found two of the fourteen**; twelve were
+converted by hand.
+
 **And a menu opens from a finger, through the event it already has.**
 `utils/long-press.ts` is one document-capture listener installed once
 from `index.ts`: a touch that holds still for 500 ms dispatches a
@@ -1725,9 +1801,140 @@ where the zero value has to be the intended answer, so an existing
 `config.toml` with no key gets the new default without a migration.
 Inline, the icon becomes the mute toggle and is named after that action
 rather than after the state, because with the slider beside it there is
-nothing left to disclose. It stands down below 600px whatever the
-setting says — that is about the platform rather than preference, and
-is why `mediacontrols`' Android handler implements no volume callback.
+nothing left to disclose. The bar's copy stands down below 600px, which
+is about *room*: five controls and a slider do not fit a 360px bar, and
+`now-playing-view` is where seeking and volume go on a phone.
+
+**Whether there is a volume to control at all is a different question,
+and it is asked of the player** (#64). On Android the hardware keys are
+the volume control and the framework mixes our stream against the
+device level, so `player`'s own level is pinned at maximum, `SetVolume`
+/ `ChangeVolume` / `MuteToggle` are refused, and `volume-control`
+renders `nothing` — in both of its mount points, at every width.
+`mediacontrols`' Android handler implementing no volume callback is the
+same fact one layer down.
+
+Five things about it are load-bearing.
+
+**It could not be a width, and that is not a preference.** Every other
+stand-down rule in this app is keyed on a viewport, because a width is
+what a browser can answer and what every tier can test. This one is a
+property of the build: keyed on width, an Android *tablet* at 600px or
+more draws the bottom bar's slider over a pinned level — a control that
+cannot act, on exactly the platform the rule exists for, which
+`library-status-indicator` already settled is worse than none. The
+same rule is wrong in the other direction below 600px, where a narrow
+desktop window has no hardware keys to fall back on.
+
+**The predicate is named after the capability, not the platform.**
+`SystemOwnsVolume` is what the frontend asks; `platformOwnsVolume` is
+the one build-tagged constant behind it, in two files that declare
+nothing else. That is `mediacontrols`' split with
+`androidpayload.go`'s reasoning: a tagged file is compiled by nothing
+`make lint` or `make test` runs, so everything decidable off a phone is
+decided against `Player.systemVolume`, a field a test sets either way.
+The frontend's absent branch is therefore testable in the component
+tier with a stubbed binding, and the constant itself is covered by a
+source sweep plus, once, a real arm64 device answering `true` — which
+is the only tier that compiles the `android` file at all.
+
+**Mute goes with it, because it is a level of zero by another name** —
+and because with no control rendered it is the one state on such a
+platform the user could not get out of.
+
+**Nothing persists a level nobody chose.** The maximum the player runs
+at is synthetic, so `restoreStateLocked` *remembers* the stored volume
+instead of applying it and `saveState` writes that same value back.
+The alternative — a second query that omits the column — buys nothing
+and is a second write path to keep in step.
+
+**And ducking is untouched, which is what makes the pin safe.**
+`SetDuck` applies its attenuation by re-applying the *user's* level
+through `setVolumeLocked`, so pinning that level to maximum leaves the
+offset arithmetic exactly as it was. It is the only thing that may move
+the output on such a platform, and it is the one volume-shaped path
+that is not refused.
+
+One thing to know before anyone offers to test it on a phone: **the
+duck is unreachable above API 25.** `WailsForegroundService` builds its
+`AudioFocusRequest` without `setWillPauseWhenDucked` from Oreo, so the
+framework attenuates us itself and never sends
+`AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK` — a device confirms it by logging
+`requestAudioFocus() … flags=0x0`. `minSdk` is 21, so this is live code
+rather than dead, on Android 5.0 to 7.1 and nowhere else.
+
+**And below 600px that bar carries three controls, not five** (#59).
+Shuffle, repeat and the queue button leave it; what is left is art,
+title/artist, favourite, and prev/play/next. `player-controls` is one
+component in two places and **the context is a property rather than a
+media query**, which is the exception to the rule two paragraphs down:
+on a phone the bar wants three controls and `now-playing-view` wants
+five, larger still, *at the same viewport* — so the host states the
+context and the viewport states the size band, and neither alone can
+express it. Sizes come from `--yj-control-*` custom properties set per
+context; play/pause alone goes above the 44px floor, because a row of
+identical squares says every action is equally likely and that is not
+true of play. Measured before #56: every one of them was **33×21px**,
+and the mini bar's favourite was **18×14**, the smallest control in the
+app.
+
+Four things about it are load-bearing.
+
+**The phone draws three buttons rather than hiding two**, from
+`matchMedia` — `job-band`'s pattern, and the rule that a decision about
+whether an element *exists* is not a stylesheet's to make. A
+`display: none` control is still in the shadow root and still something
+a positional query finds, so "the phone has three controls" would have
+been true of the pixels and false of the element.
+
+**Removing a control is only allowed because it is still reachable.**
+Plan 018's matrix promises no action is unreachable at any supported
+size, and all three are on `now-playing-view`, one tap away through the
+mini player's art. That promise is what `phone-transport.spec.ts`
+asserts — it walks the route — rather than counting buttons.
+
+**So the route to Now Playing must not depend on what is playing**, and
+it did. `now-playing` renders two branches and the no-track one had no
+`.expand` button on its placeholder, so with nothing loaded there was
+no way to the full-screen view — which, once the queue button left the
+bar, made the *queue* unreachable. The queue is persisted across
+restarts, so "tracks queued, nothing playing" is a state the app
+launches into.
+
+**The desktop bar is untouched and a spec says so with a literal.**
+Both issues are `Platform/Android`. The trap is that a `<button>` does
+not inherit its font from its parent — the UA stylesheet gives it one —
+so a generic `font-size: inherit` is not the no-op it reads as: it took
+every desktop button from 33×21 to 36×24, silently. The sizes are
+asserted as `'33x21'` rather than as a range, because the regression
+was three pixels.
+
+**What that bar lost is how far through the song it is, and
+`<player-progress-line>` is where it went** (#58). Plan 016 B2 took the
+seek bar off the phone's transport, so the one thing a mini player is
+expected to say without being opened had nowhere left to be said. It is
+a 2px line on the border between the mini player and the tab bar: the
+**shell's** element and its own `auto` grid row between `bottom-bar`
+and `bottom-nav`, because those two are separate components and either
+one drawing it means reaching into the other's box for two pixels.
+
+Four things about it are load-bearing. **It never counts** — the fill is
+`scaleX()` off the same `PlaybackPositionChanged` the seek bar renders,
+with the same `trackChangeId` and `seq` guards and an interval that is
+stopped and restarted by every report, which is the rule that exists
+because a local clock drifted 30 s away across four keyboard seeks.
+**It is not a control and cannot become one**: `aria-hidden` on the host
+and `pointer-events: none` throughout, because Now Playing's seek bar
+is what announces the position and a 2px strip on the top edge of the
+tab bar is exactly where a thumb aiming at a tab lands. **It renders
+nothing above 600px**, from `matchMedia` rather than a media query, for
+`job-band`'s reason plus one of its own — a stylesheet cannot stop a
+1 Hz interval running for the life of every desktop session about a
+line nobody can see. And **its phone rule sits at the foot of
+`index.css`, beside `job-band`'s**, not in the phone block above: a
+media query adds no specificity, so a `display: block` written before
+the `display: none` that takes it out of the desktop grid loses to it
+and the line never appears at any width, silently.
 
 **900 is the worst desktop width, not the 800×600 minimum.** The
 sidebar collapses to icons *below* 900, so the main panel is 843px at
@@ -2309,6 +2516,31 @@ missing half; `catalogFailed` is the only route to `unavailable` now,
 and the timer is a 60 s backstop for a genuine hang rather than the
 verdict.
 
+**On a phone that page is one scroll container, and the header is in
+it** (#66). It was built as a fixed header over a scrolling tracklist,
+which is the desktop arrangement: at the reference device's 424×439 the
+header owned **253 of the panel's 318px** and the list scrolled inside
+the 64 that were left. Below 600px the *host* is the scroller and
+`.content` stops being one, so the whole page moves together — which is
+only available because this tracklist is plain DOM rather than a
+virtualizer, and because `.main-panel > *` already gives the host a
+definite height.
+
+Three things about it are load-bearing. **Another `min-width: 0` was
+not the fix**: `.album-info` carries one and was shrinking exactly as
+asked, to 112px beside a 200px cover — so the title drew as `G…` and
+"Shuffle album" ended at x=443 inside a 424px box, clipped by the
+component's own `overflow: hidden` and reachable by no gesture. A row
+with a fixed-size sibling has to **stack** at that width, or the column
+that must shrink has nothing to be wide with. **`layout-overflow.spec.ts`
+cannot see any of this** — `body.scrollWidth` equalled the viewport
+throughout, because the overflow was *inside* a component; the spec
+measures each header control against the host's own box, which is
+`top-bar-fit.spec.ts`'s shape for the same reason. And **the phone block
+is last in the stylesheet**, on `index.css`'s rule: a media query adds
+no specificity, so written above the plain rules it overrides every
+declaration in it is silently dead.
+
 **Activating a row plays the list the row is in, from that row.** A
 double-click — and Play on a single row's context menu — queues the
 list as *displayed* with `startIndex` on that row, not a queue of one
@@ -3264,6 +3496,27 @@ android-inspect` forwards the WebView's devtools socket and `make
 android-eval` asks the real page — raw CDP, because `connectOverCDP`
 calls `Browser.setDownloadBehavior` and a WebView refuses it.
 
+**One of those gaps is checked rather than remembered.** A nested rule
+whose selector starts with an element name is not a parse error anyone
+would notice on 113 — the rule simply does not exist, there and nowhere
+else, which is how the bottom bar's `text-overflow: ellipsis` came to
+have never truncated on the device. `make css-check`
+(`frontend/scripts/check-css-nesting.mjs`, a pre-commit hook and a CI
+step) fails on one, over every `frontend/*.css` and the `css` literals
+alike — a glob rather than `index.css` by name, because the hook fires
+on `frontend/**/*.{ts,css}` and a sweep that names one file goes green
+over a stylesheet it never opened — and
+says the fix is a leading `&` — valid in both syntaxes, so no nested
+rule here has a reason to omit it. Two things it has to get right, and
+both follow from asking whether a *style* rule is anywhere above rather
+than what the immediate parent is: `@media (…) { bottom-nav { … } }` at
+the top level is an ordinary rule and is the majority of what a regex
+over the file would report, while the same rule one level inside
+`.bar { @media (…) { … } }` is nested and is flagged. The check is the
+cheap version of the answer; a build-time downlevel (Lightning CSS
+targeting 113) would fix the class permanently and is a dependency and
+a build step rather than twenty lines.
+
 `build/config.yml`'s `version` is the
 *metadata* version and is not what the app reports — `main.version` is
 stamped at link time from the packaging recipe's git-derived version.

Makefile

@@ -172,12 +172,17 @@ ui-setup: ## Install the Vitest browser provider's own Chromium (once)
 bindings-check: ## Fail if the generated bindings are stale
 	@./scripts/bindings-check.sh
 
+# Two CSS traps that report a long way from their cause, or not at all.
 # A backtick inside a comment in a css`` literal ends the literal, and
 # what you get back is a type error about CSSResult, or every test in
-# the suite failing to import. Four sessions, three plans. Instant.
+# the suite failing to import. Four sessions, three plans. And a nested
+# rule starting with an element name is dropped by the device's
+# Chrome 113 in silence -- no tier here runs an engine that can see it.
+# Instant.
 .PHONY: css-check
-css-check: ## Fail if a css`` literal was ended early by a backtick in a comment
+css-check: ## Fail on a css`` literal ended early by a backtick, or a nested rule needing an &
 	@cd frontend && node scripts/check-css-literals.mjs
+	@cd frontend && node scripts/check-css-nesting.mjs
 
 # .pi/ and CLAUDE.md document commands, and a doc that documents a
 # command wrongly is worse than no doc: an agent runs it confidently.

backend/player/player.go

@@ -71,6 +71,19 @@ type Player struct {
 	// not something the user chose.
 	duckAmount float64
 
+	// systemVolume is what SystemOwnsVolume answers: the platform's own
+	// control is the only one, so ours neither acts nor persists.  It is
+	// a field rather than the build constant read directly so that a
+	// test can exercise both sides on any machine.  See systemvolume.go.
+	systemVolume bool
+
+	// storedVolume and storedMuted hold the persisted level as it was
+	// found at restore, for a platform whose volume we do not own: the
+	// maximum we then run at is not a level the user chose, so saveState
+	// writes back what it read rather than overwriting it.
+	storedVolume UserVolume
+	storedMuted  bool
+
 	// trackLengthMs holds the authoritative track duration in
 	// milliseconds, sourced from the database (which uses the
 	// custom header parser).  The go-mp3 decoder's Len() can be
@@ -156,6 +169,8 @@ func NewPlayer(logger *slog.Logger, db *database.DB) *Player {
 		logger:       logger,
 		db:           db,
 		state:        Stopped,
+		systemVolume: platformOwnsVolume,
+		storedVolume: DefaultUserVol,
 		baseStreamer: generators.Silence(-1),
 		format: beep.Format{
 			SampleRate: speakerSampleRate,
@@ -875,6 +890,10 @@ func (p *Player) SetVolume(desiredVolume UserVolume) {
 	p.mu.Lock()
 	defer p.mu.Unlock()
 
+	if p.systemVolume {
+		return
+	}
+
 	p.setVolumeLocked(desiredVolume)
 	p.emitVolumeChanged()
 	p.saveState()
@@ -923,6 +942,10 @@ func (p *Player) ChangeVolume(deltaVolume int) error {
 	p.mu.Lock()
 	defer p.mu.Unlock()
 
+	if p.systemVolume {
+		return nil
+	}
+
 	p.setVolumeLocked(p.getUserVolume() + UserVolume(deltaVolume))
 	p.emitVolumeChanged()
 	p.saveState()
@@ -953,6 +976,14 @@ func (p *Player) MuteToggle() error {
 		return errNoAudioFileLoaded
 	}
 
+	// Mute is a level of zero by another name, so it goes with the rest
+	// of the volume where the system owns it -- and it would be the one
+	// state on such a platform the user could not get out of, since with
+	// no control rendered there is nothing left to un-mute with.
+	if p.systemVolume {
+		return nil
+	}
+
 	speaker.Lock()
 	p.volume.Silent = !p.volume.Silent
 	speaker.Unlock()
@@ -1403,7 +1434,15 @@ func (p *Player) saveState() {
 	volume := int64(DefaultUserVol)
 	muted := false
 
-	if p.volume != nil {
+	switch {
+	case p.systemVolume:
+		// The maximum this platform runs at is not a level anybody
+		// chose, so it is not one to remember.  Writing back what
+		// restore found keeps the row a description of the user's
+		// setting without needing a second query that omits the column.
+		volume = int64(p.storedVolume)
+		muted = p.storedMuted
+	case p.volume != nil:
 		volume = int64(p.getUserVolume())
 		muted = p.volume.Silent
 	}
@@ -1487,11 +1526,20 @@ func (p *Player) restoreStateLocked() {
 		}
 	}
 
-	vol := clampVolume(UserVolume(state.Volume))
-	p.setVolumeLocked(vol)
+	if p.systemVolume {
+		// Remembered, not applied: the device's keys are the volume
+		// control here, so the player runs wide open and hands the
+		// stored level back untouched at the next save.
+		p.storedVolume = clampVolume(UserVolume(state.Volume))
+		p.storedMuted = state.Muted
+		p.setVolumeLocked(MaxUserVol)
+	} else {
+		vol := clampVolume(UserVolume(state.Volume))
+		p.setVolumeLocked(vol)
 
-	if state.Muted {
-		p.volume.Silent = true
+		if state.Muted {
+			p.volume.Silent = true
+		}
 	}
 
 	// Restore last track if the file still exists.
@@ -1531,8 +1579,9 @@ func (p *Player) restoreStateLocked() {
 	}
 
 	p.logger.Info("Player state restored",
-		"volume", vol,
-		"muted", state.Muted,
+		"volume", p.getUserVolume(),
+		"muted", p.volume.Silent,
+		"systemVolume", p.systemVolume,
 		"trackPath", state.LastTrackPath,
 		"positionSeconds", state.LastPositionSeconds,
 	)

backend/player/systemvolume.go

@@ -0,0 +1,42 @@
+package player
+
+// Who owns the volume, and what follows when it is not us.
+//
+// On Android the hardware keys *are* the volume control and the
+// framework mixes our stream against the device level, so a second
+// control inside the app is a slider that moves something the user
+// already moved (#64).  Where that is true the player's own level sits
+// at maximum, nothing changes it, and nothing persists it.
+//
+// **The predicate is named after the capability, not the platform.**
+// The frontend asks "is there a volume for me to control", which is a
+// question about this build; asking "is this a phone" instead would
+// key the answer to a viewport, and an Android tablet at 600px or more
+// would then draw the bottom bar's slider over a level pinned at
+// maximum -- a control that cannot act, which is the thing
+// `library-status-indicator` already settled is worse than none.
+//
+// **Only `platformOwnsVolume` is behind a build tag**, in two files
+// that declare nothing else.  A tagged file is compiled by nothing
+// `make lint` or `make test` runs and is untestable off a phone, which
+// is the reasoning `mediacontrols/androidpayload.go` states for
+// keeping its contract out of one -- so everything decidable here is
+// decided against `Player.systemVolume`, a field a test sets either
+// way, and the tag decides only what that field starts as.
+//
+// The one thing this must not disturb is ducking.  `SetDuck` applies
+// its attenuation by re-applying the *user's* level through
+// `setVolumeLocked`, so pinning that level to maximum leaves the
+// offset arithmetic exactly as it was: an OS asking us to get out of
+// the way of a navigation prompt is not the user setting a volume, and
+// it is the only thing that may move the output on such a platform.
+
+// SystemOwnsVolume reports whether the platform's own control is the
+// only volume control there is, so this app neither offers one nor
+// remembers a level.
+//
+// It is bound: the frontend renders no `<volume-control>` when it is
+// true, at any width.
+func (p *Player) SystemOwnsVolume() bool {
+	return p.systemVolume
+}

backend/player/systemvolume_android.go

@@ -0,0 +1,11 @@
+//go:build android
+
+package player
+
+// platformOwnsVolume is true on Android: volume is the device's, set
+// with the hardware keys, and `mediacontrols`' Android handler
+// implements no volume callback for the same reason.
+//
+// See systemvolume.go for why this constant is the whole of what a
+// build tag decides here.
+const platformOwnsVolume = true

backend/player/systemvolume_other.go

@@ -0,0 +1,10 @@
+//go:build !android
+
+package player
+
+// platformOwnsVolume is false everywhere but Android: a desktop mixer
+// is per-application, so our level is the one the user reaches for.
+//
+// See systemvolume.go for why this constant is the whole of what a
+// build tag decides here.
+const platformOwnsVolume = false

backend/player/systemvolume_test.go

@@ -0,0 +1,215 @@
+package player
+
+import (
+	"log/slog"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/gopxl/beep/v2/effects"
+
+	"yellowjacket/backend/database"
+)
+
+// pinnedPlayer is a player on a platform whose volume belongs to the
+// device.  The field is set rather than the build constant read,
+// because the constant is true on exactly one platform and no tier
+// here runs on it -- see systemvolume.go.
+func pinnedPlayer(t *testing.T, db *database.DB) *Player {
+	t.Helper()
+
+	p := NewPlayer(slog.Default(), db)
+	p.systemVolume = true
+	p.volume = &effects.Volume{Base: 2}
+	p.setVolumeLocked(MaxUserVol)
+
+	return p
+}
+
+// TestSystemVolumeRefusesEveryWayToChangeTheLevel is the first half of
+// #64: where the device owns the volume, ours sits at maximum and none
+// of the three routes to a level moves it.  Mute is in that list
+// because it is a level of zero by another name, and because with no
+// control rendered it is the one state on such a platform there would
+// be nothing to get out of.
+func TestSystemVolumeRefusesEveryWayToChangeTheLevel(t *testing.T) {
+	t.Parallel()
+
+	p := pinnedPlayer(t, nil)
+
+	if !p.SystemOwnsVolume() {
+		t.Fatal("SystemOwnsVolume() = false on a pinned player")
+	}
+
+	if got := p.getUserVolume(); got != MaxUserVol {
+		t.Errorf("starting volume = %d, want %d", got, MaxUserVol)
+	}
+
+	p.SetVolume(20)
+
+	if got := p.getUserVolume(); got != MaxUserVol {
+		t.Errorf("volume after SetVolume(20) = %d, want %d", got, MaxUserVol)
+	}
+
+	if err := p.ChangeVolume(-30); err != nil {
+		t.Fatalf("ChangeVolume: %v", err)
+	}
+
+	if got := p.getUserVolume(); got != MaxUserVol {
+		t.Errorf("volume after ChangeVolume(-30) = %d, want %d", got, MaxUserVol)
+	}
+
+	if err := p.MuteToggle(); err != nil {
+		t.Fatalf("MuteToggle: %v", err)
+	}
+
+	if p.volume.Silent {
+		t.Error("MuteToggle silenced a player whose volume the system owns")
+	}
+}
+
+// TestAnUnpinnedPlayerStillChangesItsVolume is the other side of the
+// same switch.  Without it the test above passes on a player that
+// refuses everything, which is what a mis-wired field would produce.
+func TestAnUnpinnedPlayerStillChangesItsVolume(t *testing.T) {
+	t.Parallel()
+
+	p := NewPlayer(slog.Default(), nil)
+	p.volume = &effects.Volume{Base: 2}
+	p.setVolumeLocked(MaxUserVol)
+
+	if p.SystemOwnsVolume() {
+		t.Fatal("SystemOwnsVolume() = true off Android")
+	}
+
+	p.SetVolume(20)
+
+	if got := p.getUserVolume(); got != 20 {
+		t.Errorf("volume after SetVolume(20) = %d, want 20", got)
+	}
+
+	if err := p.MuteToggle(); err != nil {
+		t.Fatalf("MuteToggle: %v", err)
+	}
+
+	if !p.volume.Silent {
+		t.Error("MuteToggle did not silence an ordinary player")
+	}
+}
+
+// TestSystemVolumeStillDucks is the issue's second Finding, made a
+// test: pinning the user's level must leave the OS's attenuation
+// working, because a duck is not a volume the user chose and is the
+// only thing that may move the output on such a platform.
+func TestSystemVolumeStillDucks(t *testing.T) {
+	t.Parallel()
+
+	p := pinnedPlayer(t, nil)
+	open := p.volume.Volume
+
+	p.SetDuck(true)
+
+	if p.volume.Volume >= open {
+		t.Errorf(
+			"ducked output = %v, want less than %v", p.volume.Volume, open,
+		)
+	}
+
+	if got := p.getUserVolume(); got != MaxUserVol {
+		t.Errorf("user volume while ducked = %d, want %d", got, MaxUserVol)
+	}
+
+	// A refused SetVolume must not disturb the offset either: it
+	// returns before setVolumeLocked, which is what re-applies it.
+	ducked := p.volume.Volume
+
+	p.SetVolume(10)
+
+	if p.volume.Volume != ducked {
+		t.Errorf(
+			"output after a refused SetVolume = %v, want %v",
+			p.volume.Volume, ducked,
+		)
+	}
+
+	p.SetDuck(false)
+
+	if p.volume.Volume != open {
+		t.Errorf("output after unduck = %v, want %v", p.volume.Volume, open)
+	}
+}
+
+// TestSystemVolumeWritesBackTheLevelItFound is the rest of the
+// Direction: "make sure nothing writes a persisted volume from that
+// platform".  The maximum the player runs at is synthetic, so saving
+// must not record it over whatever the row already said.
+func TestSystemVolumeWritesBackTheLevelItFound(t *testing.T) {
+	t.Parallel()
+
+	db := database.NewTestDB(t)
+
+	// A level set by some earlier, unpinned session.
+	writer := NewPlayer(slog.Default(), db)
+	writer.volume = &effects.Volume{Base: 2}
+	writer.setVolumeLocked(30)
+	writer.SaveState()
+
+	p := pinnedPlayer(t, db)
+	p.RestoreState()
+
+	if got := p.getUserVolume(); got != MaxUserVol {
+		t.Errorf("restored volume = %d, want %d (the level is pinned)", got, MaxUserVol)
+	}
+
+	if p.volume.Silent {
+		t.Error("restore muted a player whose volume the system owns")
+	}
+
+	p.SaveState()
+
+	state, err := db.Queries.GetPlayerState(db.Ctx)
+	if err != nil {
+		t.Fatalf("GetPlayerState: %v", err)
+	}
+
+	if state.Volume != 30 {
+		t.Errorf("persisted volume = %d, want 30 (untouched)", state.Volume)
+	}
+}
+
+// TestPlatformVolumeOwnershipIsDeclaredOncePerPlatform sweeps the
+// source, because the pair of tagged files is the one thing here no
+// tier compiles both halves of: `make lint` and `make test` build the
+// `!android` side only, so a deleted or edited android file fails
+// nothing until somebody has a phone in their hand.
+func TestPlatformVolumeOwnershipIsDeclaredOncePerPlatform(t *testing.T) {
+	t.Parallel()
+
+	want := map[string]string{
+		"systemvolume_other.go":   "const platformOwnsVolume = false",
+		"systemvolume_android.go": "const platformOwnsVolume = true",
+	}
+
+	tags := map[string]string{
+		"systemvolume_other.go":   "//go:build !android",
+		"systemvolume_android.go": "//go:build android",
+	}
+
+	for name, decl := range want {
+		src, err := os.ReadFile(filepath.Join(".", name))
+		if err != nil {
+			t.Errorf("%s: %v", name, err)
+
+			continue
+		}
+
+		if !strings.Contains(string(src), decl) {
+			t.Errorf("%s does not declare %q", name, decl)
+		}
+
+		if !strings.Contains(string(src), tags[name]) {
+			t.Errorf("%s does not carry %q", name, tags[name])
+		}
+	}
+}

e2e/specs/phone-album-page.spec.ts

@@ -0,0 +1,209 @@
+import { test, expect } from '../support/fixtures.js';
+import type { Page } from '@playwright/test';
+
+/**
+ * The album page on a phone (#66).
+ *
+ * Two faults, and neither was visible to `layout-overflow.spec.ts`:
+ * that spec asserts the *shell* needs no sideways scrolling, and the
+ * shell was correct throughout — `body.scrollWidth === clientWidth`
+ * while `explore-album-details` itself measured 443 inside a 424px box
+ * and clipped two of the album's three primary actions with its own
+ * `overflow: hidden`. So the measurement here is **per control against
+ * the component's box**, which is the same shape `top-bar-fit.spec.ts`
+ * needed for the same reason.
+ *
+ * The other half is the scroll: the page was a fixed header over a
+ * scrolling tracklist, so at the reference device's 424x439 the header
+ * owned 253 of the panel's 318px and the list scrolled in the 64 that
+ * were left. It is one scroll container below 600px, which is a
+ * property of the *host* rather than of `.content`.
+ *
+ * The engine is the caveat this tier cannot close: the reference device
+ * renders in Chrome 113 and this is Chromium/WebKit. A flex direction
+ * and a scroll container are nowhere near that engine's documented gaps
+ * (relaxed nesting, the Popover API, `light-dark()`), but "it renders
+ * at that size in Chromium" is not evidence about the phone.
+ */
+
+/** The phone this was measured on, in CSS pixels. */
+const DEVICE = { width: 424, height: 439 };
+
+const details = (page: Page) => page.locator('explore-album-details');
+
+/** The page's own boxes, read from inside its shadow root. */
+const geometry = (page: Page) =>
+  page.evaluate(() => {
+    const host = document.querySelector('explore-album-details');
+    const sr = host?.shadowRoot;
+
+    if (!host || !sr) return null;
+
+    const box = (sel: string) => {
+      const el = sr.querySelector(sel);
+
+      if (!el) return null;
+
+      const r = el.getBoundingClientRect();
+
+      return { width: Math.round(r.width), right: Math.round(r.right) };
+    };
+
+    const content = sr.querySelector('.content');
+
+    return {
+      hostWidth: host.clientWidth,
+      hostScrollWidth: host.scrollWidth,
+      // The host is the scroller below 600px, so the page is taller
+      // than its box rather than the tracklist being a window inside it.
+      hostScrolls: host.scrollHeight > host.clientHeight,
+      contentScrolls: content
+        ? content.scrollHeight > content.clientHeight
+        : null,
+      header: box('.album-header'),
+      play: box('[data-testid="album-play"]'),
+      shuffle: box('[data-testid="album-shuffle"]'),
+      queue: box('[data-testid="album-queue"]'),
+      title: (() => {
+        const el = sr.querySelector('.album-title-text');
+
+        return el ? el.scrollWidth <= el.clientWidth + 1 : null;
+      })(),
+    };
+  });
+
+test.describe('the album page on a phone', () => {
+  test.beforeEach(async ({ app }) => {
+    await app.setViewportSize(DEVICE);
+    await openFirstAlbum(app);
+  });
+
+  test.afterEach(async ({ app }) => {
+    await app.setViewportSize({ width: 1440, height: 900 });
+    await app.getByTestId('nav-tracks').click();
+  });
+
+  test('keeps every action inside its own box', async ({ app }) => {
+    const geo = await geometry(app);
+
+    expect(geo).not.toBeNull();
+    // "Shuffle album" ended at x=443 in a 424px component and could not
+    // be reached by any gesture; "Add to queue" at 440.
+    for (const action of ['play', 'shuffle', 'queue'] as const) {
+      expect(
+        geo?.[action],
+        `${action} is rendered`,
+      ).not.toBeNull();
+      expect(
+        geo?.[action]?.right ?? 0,
+        `${action} ends inside the page`,
+      ).toBeLessThanOrEqual(geo?.hostWidth ?? 0);
+    }
+
+    expect(geo?.hostScrollWidth).toBe(geo?.hostWidth);
+    expect(geo?.header?.width).toBe(geo?.hostWidth);
+  });
+
+  test('gives the title the row rather than one glyph of it', async ({
+    app,
+  }) => {
+    // `.album-info` was squeezed to 112px beside the art, so an album
+    // called *Glass Harbour* drew as `G…`. It carries `min-width: 0`
+    // and was shrinking as asked — the row had to stack.
+    expect(await geometry(app).then((g) => g?.title)).toBe(true);
+  });
+
+  test('scrolls as one page, with the header scrolling away', async ({
+    app,
+  }) => {
+    const before = await geometry(app);
+
+    expect(before?.hostScrolls).toBe(true);
+    expect(before?.contentScrolls).toBe(false);
+
+    const headerTop = () =>
+      app.evaluate(
+        () =>
+          document
+            .querySelector('explore-album-details')
+            ?.shadowRoot?.querySelector('.album-header')
+            ?.getBoundingClientRect().top ?? 0,
+      );
+
+    expect(await headerTop()).toBeGreaterThanOrEqual(0);
+
+    // A wheel gesture, not `scrollTop`: `overflow: hidden` still permits
+    // programmatic scrolling, so a probe that assigns it passes on the
+    // build this exists to fail.
+    await details(app).hover();
+    await app.mouse.wheel(0, 250);
+
+    await expect.poll(headerTop).toBeLessThan(-100);
+  });
+
+  test('is the desktop arrangement again above the breakpoint', async ({
+    app,
+  }) => {
+    await app.setViewportSize({ width: 1024, height: 800 });
+
+    // The same element, re-laid-out: one component with two
+    // arrangements, not a phone-only copy.
+    await expect
+      .poll(async () => (await geometry(app))?.hostScrolls)
+      .toBe(false);
+
+    const arrangement = await app.evaluate(() => {
+      const sr = document.querySelector('explore-album-details')?.shadowRoot;
+      const header = sr?.querySelector('.album-header');
+      const content = sr?.querySelector('.content');
+
+      return {
+        direction: header ? getComputedStyle(header).flexDirection : null,
+        contentOverflow: content ? getComputedStyle(content).overflowY : null,
+      };
+    });
+
+    expect(arrangement.direction).toBe('row');
+    expect(arrangement.contentOverflow).toBe('auto');
+  });
+});
+
+/** Albums → the second card, which navigates to the album page. */
+async function openFirstAlbum(app: Page): Promise<void> {
+  // Below 600px the sidebar is gone; the tab bar is the navigation.
+  await app.getByTestId('tab-albums').click();
+  await expect(app.getByTestId('main-content')).toHaveAttribute(
+    'data-active-view',
+    'albums',
+  );
+
+  await expect.poll(() => cardCount(app)).toBeGreaterThan(1);
+
+  // Dispatched rather than clicked: the card lives in a virtualizer
+  // inside a shadow root, and Enter expands the dropdown instead.
+  await app.evaluate(() => {
+    document
+      .querySelector('cover-grid')
+      ?.shadowRoot?.querySelectorAll('.album-card')[1]
+      ?.dispatchEvent(
+        new MouseEvent('click', { bubbles: true, composed: true }),
+      );
+  });
+
+  await expect(app.getByTestId('main-content')).toHaveAttribute(
+    'data-active-view',
+    'explore-album-details',
+  );
+  await expect(
+    details(app).locator('[data-testid="album-play"]'),
+  ).toBeVisible();
+}
+
+async function cardCount(app: Page): Promise<number> {
+  return app.evaluate(
+    () =>
+      document
+        .querySelector('cover-grid')
+        ?.shadowRoot?.querySelectorAll('.album-card').length ?? 0,
+  );
+}

e2e/specs/phone-progress-line.spec.ts

@@ -0,0 +1,136 @@
+import {
+  test,
+  expect,
+  callBinding,
+  resetEvents,
+  waitForEvent,
+  LONG_TRACK,
+  NO_QUEUE_SOURCE,
+} from '../support/fixtures.js';
+import type { Page } from '@playwright/test';
+
+/**
+ * The phone's progress line (#58).
+ *
+ * The component tier already pins what the line *says* — that it
+ * renders the backend's reported position and never a count of its own.
+ * What only a real shell can answer is **where it is**: the issue asks
+ * for a line on the border between the mini player and the tab bar, and
+ * "on the border" is two adjacencies in a grid that no component-level
+ * render has around it.
+ *
+ * It also asserts the line is not there on a desktop, which is the
+ * other half of the same fact: above 600px there is no tab bar for it
+ * to sit on the border of, and the bar carries a real seek bar.
+ */
+type Rect = { x: number; y: number; width: number; height: number };
+
+/** The reference device's real viewport. */
+const DEVICE = { width: 424, height: 439 };
+const DESKTOP = { width: 1280, height: 800 };
+
+async function rectOf(app: Page, selector: string): Promise<Rect | null> {
+  return app.evaluate((sel) => {
+    const el = document.querySelector(sel);
+
+    if (!el) return null;
+
+    const r = el.getBoundingClientRect();
+
+    return { x: r.x, y: r.y, width: r.width, height: r.height };
+  }, selector);
+}
+
+/**
+ * Put the 90-second fixture on and wait for the first position report.
+ *
+ * The long track rather than any track: every other fixture is 2-6
+ * seconds, which is shorter than the time this spec takes to measure
+ * three rectangles.
+ */
+async function play(app: Page): Promise<void> {
+  const tracks = await callBinding<{ FilePath: string; TrackName: string }[]>(
+    app,
+    'library.Library.GetTracks',
+    [0],
+  );
+
+  // `TrackName`, not `Title`: that is what the library model calls it.
+  const long = tracks.find((t) => t.TrackName === LONG_TRACK);
+
+  expect(long, `no fixture track named ${LONG_TRACK}`).toBeTruthy();
+
+  await callBinding(app, 'queue.Queue.Clear');
+  await resetEvents(app);
+  await callBinding(app, 'queue.Queue.SetQueue', [
+    [long!.FilePath],
+    0,
+    false,
+    NO_QUEUE_SOURCE,
+  ]);
+  await waitForEvent(app, 'QueueChanged');
+  await callBinding(app, 'queue.Queue.Play');
+  await waitForEvent(app, 'PlaybackPositionChanged', { timeoutMs: 15_000 });
+}
+
+test.describe('the progress line sits on the border between the bars', () => {
+  test.beforeEach(async ({ app }) => {
+    await app.setViewportSize(DEVICE);
+    await play(app);
+  });
+
+  /*
+   * Every test here starts a LONG_TRACK and the suite is workers: 1,
+   * fullyParallel: false against one long-lived app — so without this
+   * the four phone-* specs that follow alphabetically inherit a playing
+   * queue. phone-transport.spec.ts records where that lesson came from:
+   * the fault first showed up as a flake in a spec about something else.
+   */
+  test.afterEach(async ({ app }) => {
+    await callBinding(app, 'queue.Queue.Clear').catch(() => {
+      /* already empty */
+    });
+    await app.setViewportSize(DESKTOP);
+  });
+
+  test('spans the width, between the mini player and the tab bar', async ({
+    app,
+  }) => {
+    const line = await rectOf(app, 'player-progress-line');
+    const bar = await rectOf(app, '.bottom-bar');
+    const nav = await rectOf(app, 'bottom-nav');
+
+    expect(line, 'no progress line on the phone').not.toBeNull();
+    expect(bar).not.toBeNull();
+    expect(nav).not.toBeNull();
+
+    // A border, not a band: 2px, the full width, and touching both.
+    expect(line!.height).toBeCloseTo(2, 0);
+    expect(line!.width).toBeCloseTo(bar!.width, 0);
+    expect(line!.y).toBeCloseTo(bar!.y + bar!.height, 0);
+    expect(nav!.y).toBeCloseTo(line!.y + line!.height, 0);
+  });
+
+  /**
+   * It is 2px on the top edge of the tab bar, which is exactly where a
+   * thumb aiming at a tab lands. A line that sometimes seeks is worse
+   * than one that never does, so it must take no part in hit testing
+   * at all.
+   */
+  test('takes no taps', async ({ app }) => {
+    const line = await rectOf(app, 'player-progress-line');
+
+    const hit = await app.evaluate(
+      ({ x, y }) => document.elementFromPoint(x, y)?.tagName ?? '',
+      { x: line!.x + line!.width / 2, y: line!.y + 1 },
+    );
+
+    expect(hit).not.toBe('PLAYER-PROGRESS-LINE');
+  });
+
+  test('is not there on a desktop', async ({ app }) => {
+    await app.setViewportSize(DESKTOP);
+
+    await expect(app.locator('player-progress-line')).toBeHidden();
+  });
+});

e2e/specs/phone-shell.spec.ts

@@ -130,6 +130,25 @@ test.describe('the shell on a phone', () => {
     // are here, and they are the *same* components -- this view
     // composes the transport rather than reimplementing it.
     await expect(app.locator('now-playing-view seek-bar')).toBeVisible();
+
+    // Volume is here **because the player says there is one** (#64),
+    // not because this is a phone. This tier is the platform that owns
+    // its own volume, so what it can assert is that the control's
+    // presence follows that answer -- an inverted polarity in
+    // `volume-style-store` fails here and in `bottom-bar.spec.ts`, and
+    // the *absent* branch is checked in the component tier, where the
+    // binding can be stubbed. Nothing here can reach the Android side.
+    const systemOwns = await app.evaluate(
+      async () =>
+        (await window.__yjEvents.call(
+          'player.Player.SystemOwnsVolume',
+          [],
+          5_000,
+        )) as boolean,
+    );
+
+    expect(systemOwns, 'this platform should own its own volume').toBe(false);
+
     await expect(app.locator('now-playing-view volume-control')).toBeVisible();
 
     // Back goes where the user came from, through the nav stack.

e2e/specs/phone-transport.spec.ts

@@ -0,0 +1,315 @@
+import { test, expect } from '../support/fixtures.js';
+
+/**
+ * The phone's transport (#59, #56).
+ *
+ * #56 reports that "the playback controls are the most important thing
+ * in the mobile app and they are tiny". Measured at the reference
+ * device's 424x439 before this, every one of them was **33x21px**, and
+ * the favourite beside them — which #59 keeps on the bar — was
+ * **18x14px**, the smallest control in the app.
+ *
+ * #59 is what makes the sizes affordable: five controls plus a queue
+ * button at 44px does not fit 424 CSS px, so the bar carries three and
+ * the rest are on the full-screen view.
+ *
+ * **The assertion that matters is not the pixel count.** Plan 018's
+ * matrix promises that *no action is ever unreachable at any supported
+ * size*, and #59 removes three controls from the phone's bar — so the
+ * first thing this file checks is that all three are still reachable,
+ * by walking the route a user would. A spec that only measured the
+ * survivors would be green on a build that had made shuffle
+ * unreachable, which is the failure mode this pair of issues is one
+ * mistake away from.
+ */
+type Page = import('@playwright/test').Page;
+
+/** The reference device's real viewport. */
+const DEVICE = { width: 424, height: 439 };
+const PHONE = { width: 390, height: 780 };
+const DESKTOP = { width: 1280, height: 800 };
+
+/**
+ * The touch-target floor. 44px is what #56's Findings name and what
+ * #55's queue header was sized to, so the app has one number.
+ */
+const TARGET = 44;
+
+/** The play button is named for its action, not its identity. */
+const PLAY_PAUSE = /^(Play|Pause)$/;
+
+const barControls = (page: Page) =>
+  page.locator('audio-player player-controls');
+
+/**
+ * `name` may be a regex, and for play/pause it must be: that button is
+ * named for the *action*, so it is "Pause" while a track runs and
+ * "Play" when it stops. An exact 'Play' made these tests wait out a
+ * fixture track (11.1s each, passing by luck) and would have failed
+ * outright against `LONG_TRACK`. A test about a control's size does not
+ * care what the transport is doing.
+ */
+async function sizeOf(
+  page: Page,
+  name: string | RegExp,
+): Promise<[number, number]> {
+  const box = await page
+    .getByRole('button', { name, exact: typeof name === 'string' })
+    .boundingBox();
+
+  expect(box, `no button named ${name}`).not.toBeNull();
+
+  return [box!.width, box!.height];
+}
+
+/** Put something in the queue, so the transport has a track to act on. */
+async function stageATrack(page: Page): Promise<void> {
+  await page.evaluate(async () => {
+    const tracks = (await window.__yjEvents.call(
+      'library.Library.GetTracks',
+      [0],
+      10_000,
+    )) as { FilePath: string }[];
+
+    await window.__yjEvents.call(
+      'queue.Queue.SetQueue',
+      [tracks.slice(0, 4).map((t) => t.FilePath), 0, false, { type: '', id: 0, label: '' }],
+      10_000,
+    );
+  });
+}
+
+test.describe('the phone bar carries three controls', () => {
+  test.beforeEach(async ({ app }) => {
+    await app.setViewportSize(DEVICE);
+    await stageATrack(app);
+  });
+
+  test('drops shuffle, repeat and the queue from the bar', async ({ app }) => {
+    const bar = barControls(app);
+
+    await expect(bar.getByRole('button', { name: 'Previous track' })).toBeVisible();
+    await expect(bar.getByRole('button', { name: 'Next track' })).toBeVisible();
+
+    // Not in the bar's own subtree. Asserted against the bar rather
+    // than the page, because the whole point is that they moved rather
+    // than went away -- a page-wide `not.toBeVisible()` would fail the
+    // moment Now Playing is open and would be asserting the wrong
+    // thing besides.
+    await expect(bar.getByRole('button', { name: 'Shuffle' })).toHaveCount(0);
+    await expect(bar.getByRole('button', { name: /^Repeat/ })).toHaveCount(0);
+    await expect(app.locator('#queue-button')).toBeHidden();
+  });
+
+  /**
+   * The promise, walked. Every control #59 takes off the bar is
+   * reachable from the mini player's art in one tap.
+   */
+  test('leaves every removed control reachable from Now Playing', async ({
+    app,
+  }) => {
+    await app.getByTestId('open-now-playing').click();
+
+    await expect(app.getByTestId('main-content')).toHaveAttribute(
+      'data-active-view',
+      'now-playing',
+    );
+
+    await expect(app.getByRole('button', { name: 'Shuffle' })).toBeVisible();
+    await expect(app.getByRole('button', { name: /^Repeat/ })).toBeVisible();
+    await expect(app.getByRole('button', { name: 'Show the queue' })).toBeVisible();
+  });
+
+  test('sizes what is left for a thumb', async ({ app }) => {
+    for (const name of ['Previous track', 'Next track']) {
+      const [w, h] = await sizeOf(app, name);
+
+      expect(w, `${name} width`).toBeGreaterThanOrEqual(TARGET);
+      expect(h, `${name} height`).toBeGreaterThanOrEqual(TARGET);
+    }
+
+    // Play is deliberately bigger than its neighbours: a row of
+    // identical squares says every action is equally likely, which is
+    // not true of play.
+    const [pw, ph] = await sizeOf(app, PLAY_PAUSE);
+    const [nw] = await sizeOf(app, 'Next track');
+
+    expect(ph).toBeGreaterThanOrEqual(TARGET);
+    expect(pw).toBeGreaterThan(nw);
+  });
+
+  /**
+   * The favourite was 18x14 and is one of the three controls #59
+   * keeps, so it is part of this issue rather than a nicety.
+   */
+  test('sizes the favourite, which was the smallest control in the app', async ({
+    app,
+  }) => {
+    const fav = app
+      .locator('now-playing')
+      .getByRole('button', { name: /Favorites$/ });
+
+    const box = await fav.boundingBox();
+
+    expect(box).not.toBeNull();
+    expect(box!.width).toBeGreaterThanOrEqual(TARGET);
+    expect(box!.height).toBeGreaterThanOrEqual(TARGET);
+  });
+
+  /**
+   * **The route to the queue must not depend on what is playing.**
+   *
+   * `now-playing` renders two branches, and the no-track one had no
+   * `.expand` button on its placeholder — so with nothing loaded there
+   * was no way to Now Playing, and once #59 takes the queue button off
+   * the bar that makes the *queue* unreachable. The queue is persisted
+   * across restarts, so "tracks queued, nothing playing" is a state the
+   * app launches into.
+   *
+   * This is asserted with the queue explicitly emptied rather than by
+   * relying on the app not having played anything: `make e2e` runs one
+   * long-lived app across every spec file (#168), so "no track loaded"
+   * is otherwise whatever the file before this one left behind — which
+   * is how the underlying fault first showed up as a flake in a spec
+   * about something else.
+   */
+  test('reaches the queue with nothing playing', async ({ app }) => {
+    await app.evaluate(async () => {
+      await window.__yjEvents.call('queue.Queue.Clear', [], 10_000);
+    });
+
+    await expect(app.getByTestId('open-now-playing')).toBeVisible();
+
+    await app.getByTestId('open-now-playing').click();
+    await app.getByTestId('npv-queue').click();
+
+    await expect(app.locator('#queue-panel')).toHaveAttribute('open', '');
+  });
+
+  test('still fits, with nothing to scroll sideways to', async ({ app }) => {
+    const fit = await app.evaluate(() => ({
+      scroll: document.body.scrollWidth,
+      client: document.body.clientWidth,
+    }));
+
+    expect(fit.scroll).toBe(fit.client);
+  });
+});
+
+test.describe('the full-screen transport is the page', () => {
+  test.beforeEach(async ({ app }) => {
+    await app.setViewportSize(DEVICE);
+    await stageATrack(app);
+    await app.getByTestId('open-now-playing').click();
+  });
+
+  test('draws all five, larger than the bar draws any', async ({ app }) => {
+    const [pw, ph] = await sizeOf(app, PLAY_PAUSE);
+
+    expect(pw).toBeGreaterThanOrEqual(56);
+    expect(ph).toBeGreaterThanOrEqual(56);
+
+    for (const name of ['Shuffle', 'Previous track', 'Next track']) {
+      const [w, h] = await sizeOf(app, name);
+
+      expect(w, `${name} width`).toBeGreaterThanOrEqual(TARGET);
+      expect(h, `${name} height`).toBeGreaterThanOrEqual(TARGET);
+    }
+  });
+
+  test('fits at both phone widths', async ({ app }) => {
+    for (const size of [DEVICE, PHONE]) {
+      await app.setViewportSize(size);
+
+      const fit = await app.evaluate(() => ({
+        scroll: document.body.scrollWidth,
+        client: document.body.clientWidth,
+      }));
+
+      expect(fit.scroll, `${size.width}px`).toBe(fit.client);
+    }
+  });
+});
+
+/**
+ * **The desktop bar is not what either issue is about, and must not
+ * move.** Both are `Platform/Android`; this is the guard that says so
+ * in a way a build can check.
+ *
+ * It caught a real regression while it was being written: a generic
+ * `font-size` on the buttons took them from the UA stylesheet's 13.3px
+ * to the shell's 16px and grew every one from 33x21 to 36x24 — a
+ * change nobody asked for, invisible to every other assertion here.
+ */
+test.describe('the desktop bar is untouched', () => {
+  test.beforeEach(async ({ app }) => {
+    await app.setViewportSize(DESKTOP);
+    await stageATrack(app);
+  });
+
+  test('keeps all five controls and the queue button', async ({ app }) => {
+    const bar = barControls(app);
+
+    for (const name of ['Shuffle', 'Previous track', 'Next track']) {
+      await expect(bar.getByRole('button', { name })).toBeVisible();
+    }
+
+    await expect(bar.getByRole('button', { name: /^Repeat/ })).toBeVisible();
+    await expect(app.locator('#queue-button')).toBeVisible();
+  });
+
+  /**
+   * **The mechanism, because the pixels are the engine's.**
+   *
+   * The first version of this asserted the literal `'33x21'`, measured
+   * on `main` in Chromium — and WebKit draws the same button **36x24**,
+   * so it failed in CI on a build where nothing was wrong. A button's
+   * box comes from the UA stylesheet when the author sets nothing, and
+   * what each UA sets is its own business.
+   *
+   * What this PR must not do is *set* anything here, so that is what is
+   * asserted: our two box properties are unset, and the font is still
+   * the UA's rather than the shell's. That is precisely the regression
+   * this caught the first time — a generic `font-size: inherit` took
+   * these from the UA's default to 16px — and it catches it in either
+   * engine.
+   */
+  test('sets no size of its own on the desktop bar', async ({ app }) => {
+    const measured = await barControls(app).evaluate((el) => {
+      // A bare button with no author styles: whatever this engine
+      // gives one is what the bar's buttons must still be.
+      const probe = document.createElement('button');
+
+      document.body.appendChild(probe);
+
+      const uaFontSize = getComputedStyle(probe).fontSize;
+
+      probe.remove();
+
+      return [...el.shadowRoot!.querySelectorAll('button')].map((b) => {
+        const cs = getComputedStyle(b);
+        const r = b.getBoundingClientRect();
+
+        return {
+          minWidth: cs.minWidth,
+          minHeight: cs.minHeight,
+          usesUaFont: cs.fontSize === uaFontSize,
+          size: `${Math.round(r.width)}x${Math.round(r.height)}`,
+        };
+      });
+    });
+
+    expect(measured).toHaveLength(5);
+
+    for (const m of measured) {
+      expect(m.minWidth, 'min-width').toBe('0px');
+      expect(m.minHeight, 'min-height').toBe('0px');
+      expect(m.usesUaFont, 'font-size is still the UA default').toBe(true);
+    }
+
+    // And all five are the same box: `.play` takes a larger size in
+    // both sized contexts, so this is what says the desktop is neither
+    // of them.
+    expect(new Set(measured.map((m) => m.size)).size).toBe(1);
+  });
+});

e2e/specs/queue-as-a-screen.spec.ts

@@ -1,4 +1,4 @@
-import { test, expect } from '../support/fixtures.js';
+import { test, expect, openTheQueue } from '../support/fixtures.js';
 
 /**
  * #55 — the queue is a *place* while it covers the content, and a
@@ -37,15 +37,37 @@ const DEVICE = { width: 424, height: 439 };
 /** Wide enough that the queue is a column: 1280 − 200 − 320 ≥ 480. */
 const DESKTOP = { width: 1280, height: 800 };
 
+/**
+ * The Compact band, where the queue is a *screen* (644 − 320 < 480) and
+ * the bottom bar still carries its button.
+ *
+ * Two of these tests need both facts at once and only this band has
+ * them: below 600px #59 takes the button off the bar, so there is no
+ * toggle to re-press and the queue is opened from Now Playing — which
+ * is itself a detail view, so "the destination stays lit" is vacuously
+ * true there rather than tested.
+ */
+const COMPACT = { width: 700, height: 600 };
+
 const activeView = (page: Page) => page.getByTestId('main-content');
 const queue = (page: Page) => page.locator('#queue-panel');
 const toggle = (page: Page) => page.locator('#queue-button');
 
+/**
+ * Whether the queue is up.
+ *
+ * The panel's own attribute rather than the toggle's `aria-expanded`,
+ * because below 600px there is no toggle to ask (#59) — and the panel
+ * is the one fact both of them reflect anyway.
+ */
 async function expectQueue(page: Page, open: boolean): Promise<void> {
-  await expect(toggle(page)).toHaveAttribute(
-    'aria-expanded',
-    String(open),
-  );
+  const panel = queue(page);
+
+  if (open) {
+    await expect(panel).toHaveAttribute('open', '');
+  } else {
+    await expect(panel).not.toHaveAttribute('open', '');
+  }
 }
 
 test.describe('the queue is a screen where it covers the content', () => {
@@ -55,12 +77,17 @@ test.describe('the queue is a screen where it covers the content', () => {
     await expect(activeView(app)).toHaveAttribute('data-active-view', 'albums');
   });
 
+  // On a phone the queue is opened from Now Playing (#59), so the page
+  // *underneath* it is `now-playing` and the journey is two entries
+  // deep: albums -> now-playing -> queue. That is the real route a user
+  // takes, which is why these do not reach for the shortcut.
+
   test('back closes the queue and leaves the page where it was', async ({
     app,
   }) => {
     await expect(queue(app)).toHaveAttribute('overlay', '');
 
-    await toggle(app).click();
+    await openTheQueue(app);
     await expectQueue(app, true);
 
     await app.goBack();
@@ -69,27 +96,31 @@ test.describe('the queue is a screen where it covers the content', () => {
     // The page underneath is untouched. Before #55 this was the
     // *previous* view, because the queue was not in the stack at all
     // and back spent an entry navigating something nobody could see.
-    await expect(activeView(app)).toHaveAttribute('data-active-view', 'albums');
+    await expect(activeView(app)).toHaveAttribute(
+      'data-active-view',
+      'now-playing',
+    );
   });
 
   test('costs exactly one entry, so the next press navigates', async ({
     app,
   }) => {
-    await toggle(app).click();
+    await openTheQueue(app);
     await expectQueue(app, true);
 
     await app.goBack();
     await expectQueue(app, false);
+    await expect(activeView(app)).toHaveAttribute(
+      'data-active-view',
+      'now-playing',
+    );
 
     await app.goBack();
 
-    // Whatever the launch page is, it is not Albums — the point is that
-    // this press moved the app rather than being swallowed by a queue
-    // that had already closed.
-    await expect(activeView(app)).not.toHaveAttribute(
-      'data-active-view',
-      'albums',
-    );
+    // Exactly one entry each: the second press leaves Now Playing for
+    // the page it was opened from, rather than being swallowed by a
+    // queue that had already closed.
+    await expect(activeView(app)).toHaveAttribute('data-active-view', 'albums');
   });
 
   /**
@@ -116,15 +147,9 @@ test.describe('the queue is a screen where it covers the content', () => {
         await app.keyboard.press('Escape');
       },
     ],
-    [
-      'the toggle it was opened from',
-      async (app: Page) => {
-        await toggle(app).click();
-      },
-    ],
   ] as Array<[string, (app: Page) => Promise<void>]>) {
     test(`${name} leaves no entry behind`, async ({ app }) => {
-      await toggle(app).click();
+      await openTheQueue(app);
       await expectQueue(app, true);
 
       await dismiss(app);
@@ -132,7 +157,10 @@ test.describe('the queue is a screen where it covers the content', () => {
 
       await app.goBack();
 
-      await expect(activeView(app)).not.toHaveAttribute(
+      // One press, one screen: Now Playing is what the queue was opened
+      // from, so leaving it lands on Albums. An orphaned entry would
+      // have spent this press on nothing and left it here.
+      await expect(activeView(app)).toHaveAttribute(
         'data-active-view',
         'albums',
       );
@@ -149,18 +177,6 @@ test.describe('the queue is a screen where it covers the content', () => {
    * `back-navigation.spec.ts` gives: the class was right throughout the
    * bug that rule exists for.
    */
-  test('leaves the tab it was opened from highlighted', async ({ app }) => {
-    await expect(
-      app.getByRole('button', { name: 'Albums', exact: true }),
-    ).toHaveAttribute('aria-current', 'page');
-
-    await toggle(app).click();
-    await expectQueue(app, true);
-
-    await expect(
-      app.getByRole('button', { name: 'Albums', exact: true }),
-    ).toHaveAttribute('aria-current', 'page');
-  });
 
   /**
    * With the panel spanning the whole width the scrim has no uncovered
@@ -168,7 +184,7 @@ test.describe('the queue is a screen where it covers the content', () => {
    * full-screen surface. Measured at 424×439 before #55: **25×21px**.
    */
   test('offers a way out a thumb can hit', async ({ app }) => {
-    await toggle(app).click();
+    await openTheQueue(app);
 
     const box = await app
       .getByRole('button', { name: 'Close queue' })
@@ -204,7 +220,7 @@ test('the panel stays out of the paint-contained region', async ({ app }) => {
   // from it — and because the host drops `paint` from its own
   // containment deliberately in overlay mode, so a closed panel answers
   // a different question.
-  await toggle(app).click();
+  await openTheQueue(app);
   await expectQueue(app, true);
 
   const ancestry = await app.evaluate(() => {
@@ -235,6 +251,66 @@ test('the panel stays out of the paint-contained region', async ({ app }) => {
   }
 });
 
+/**
+ * Two properties need the queue to be a *screen* and the bar to still
+ * have its button, and only the Compact band has both — below 600px #59
+ * takes the button off the bar.
+ */
+test.describe('a screen opened from the bar', () => {
+  test.beforeEach(async ({ app }) => {
+    await app.setViewportSize(COMPACT);
+    await app.getByTestId('nav-albums').click();
+    await expect(activeView(app)).toHaveAttribute('data-active-view', 'albums');
+    await expect(queue(app)).toHaveAttribute('overlay', '');
+  });
+
+  /**
+   * A detail view leaves the destination it was opened from lit
+   * (`active-view-store`, #72), and the queue inherits that — it is
+   * published with `isPrimary: false`, so `isActive('albums')` is still
+   * true underneath it.
+   *
+   * `aria-current` rather than a class, for the reason
+   * `back-navigation.spec.ts` gives: the class was right throughout the
+   * bug that rule exists for.
+   */
+  test('leaves the destination it was opened from highlighted', async ({
+    app,
+  }) => {
+    // By testid, not by role: at 700px the sidebar is in icon mode, so
+    // what the item is *named* is a different question from which item
+    // it is. The assertion is still `aria-current`, which is the
+    // accessible fact.
+    const albums = app.getByTestId('nav-albums');
+
+    await expect(albums).toHaveAttribute('aria-current', 'page');
+
+    await toggle(app).click();
+    await expectQueue(app, true);
+
+    await expect(albums).toHaveAttribute('aria-current', 'page');
+  });
+
+  /** The toggle is a fourth way out, and it unwinds the entry like the
+   *  other three — through the panel's attribute, not its own handler. */
+  test('closes from the same toggle, leaving no entry behind', async ({
+    app,
+  }) => {
+    await toggle(app).click();
+    await expectQueue(app, true);
+
+    await toggle(app).click();
+    await expectQueue(app, false);
+
+    await app.goBack();
+
+    await expect(activeView(app)).not.toHaveAttribute(
+      'data-active-view',
+      'albums',
+    );
+  });
+});
+
 /**
  * The column is not a place. Somebody docked it; back must not undock
  * it, and navigating to another view must not take it away.

e2e/specs/queue-overlay.spec.ts

@@ -1,4 +1,4 @@
-import { test, expect } from '../support/fixtures.js';
+import { test, expect, openTheQueue } from '../support/fixtures.js';
 
 /**
  * #24 — the queue panel does not take the page's width away from it.
@@ -54,15 +54,15 @@ const shellGeometry = (page: import('@playwright/test').Page) =>
     };
   });
 
-async function openQueue(page: import('@playwright/test').Page) {
-  const toggle = page.locator('#queue-button');
-
-  if ((await toggle.getAttribute('aria-expanded')) !== 'true') {
-    await toggle.click();
-  }
-
-  await expect(toggle).toHaveAttribute('aria-expanded', 'true');
-}
+/**
+ * Opening the queue is `openTheQueue`, which takes the route this
+ * viewport offers. It used to be a local helper that clicked
+ * `#queue-button` unconditionally, and #59 hid that button below
+ * 600px -- so the two phone bands here failed on a build where the
+ * queue was working perfectly, having been asserting *how* it opens as
+ * much as what it does.
+ */
+const openQueue = openTheQueue;
 
 test.describe('an open queue leaves the content its width', () => {
   for (const band of BANDS) {

e2e/support/fixtures.ts

@@ -140,6 +140,50 @@ export async function navigateTo(page: Page, view: string): Promise<void> {
     .waitFor({ state: 'attached' });
 }
 
+/**
+ * Open the queue the way a user at this viewport would.
+ *
+ * **The route differs by width and that is the feature, not an
+ * inconvenience.** Above 600px the bottom bar carries a queue button.
+ * Below it that button is gone (#59) and the queue is reached from the
+ * full-screen Now Playing view, which the mini player's art opens —
+ * "reachable only from Now Playing", which is what the issue asks for.
+ *
+ * It is here rather than in one spec because four files need it, and
+ * because a spec that hard-codes `#queue-button` is quietly asserting
+ * *which* route exists as well as what the queue does. Four of them
+ * were, which is how hiding one button failed ten tests about
+ * something else.
+ *
+ * The width is read from the page rather than passed, so a caller that
+ * resizes and then opens does not have to say so twice.
+ */
+export async function openTheQueue(page: Page): Promise<void> {
+  const toggle = page.locator('#queue-button');
+
+  if (await toggle.isVisible()) {
+    if ((await toggle.getAttribute('aria-expanded')) !== 'true') {
+      await toggle.click();
+    }
+
+    await expect(toggle).toHaveAttribute('aria-expanded', 'true');
+
+    return;
+  }
+
+  // The phone: through Now Playing. `open-now-playing` is the mini
+  // player's art, which is a button only below 600px.
+  if (
+    (await page.getByTestId('main-content').getAttribute('data-active-view')) !==
+    'now-playing'
+  ) {
+    await page.getByTestId('open-now-playing').click();
+  }
+
+  await page.getByTestId('npv-queue').click();
+  await expect(page.locator('#queue-panel')).toHaveAttribute('open', '');
+}
+
 /** Thin client for the dev-only /__test/ surface (backend/testctl). */
 export class TestCtl {
   constructor(private readonly baseURL: string) {}

frontend/bindings/yellowjacket/backend/player/player.ts

@@ -142,6 +142,18 @@ export function SetVolume(desiredVolume: $models.UserVolume): $CancellablePromis
     return $Call.ByID(1375836663, desiredVolume);
 }
 
+/**
+ * SystemOwnsVolume reports whether the platform's own control is the
+ * only volume control there is, so this app neither offers one nor
+ * remembers a level.
+ * 
+ * It is bound: the frontend renders no `<volume-control>` when it is
+ * true, at any width.
+ */
+export function SystemOwnsVolume(): $CancellablePromise<boolean> {
+    return $Call.ByID(1027623185);
+}
+
 /**
  * TrackLengthInSeconds returns the duration of the current track.
  */

frontend/index.css

@@ -426,6 +426,7 @@ body div.sidebar {
             "jobs-band" auto
             "main-panel" 1fr
             "bottom-bar" auto
+            "progress-line" auto
             "bottom-nav" auto
             / 1fr;
         /* Nothing may scroll sideways here.  On a desktop the shell is
@@ -501,7 +502,8 @@ body div.sidebar {
        expression of the same fact is a second thing to keep in step.
        The view carries its own queue button, because this is where
        that one lived. */
-    body:has(#main-content[data-active-view="now-playing"]) .bottom-bar {
+    body:has(#main-content[data-active-view="now-playing"]) .bottom-bar,
+    body:has(#main-content[data-active-view="now-playing"]) player-progress-line {
         display: none;
     }
 }
@@ -522,26 +524,58 @@ body div.sidebar {
     }
 
     /* Volume stands down here whatever the setting says, because this
-       is about room and about the platform rather than about
-       preference: the hardware keys own volume on a phone, which is
-       also why mediacontrols' Android handler implements no volume
-       callback. It moved from `audio-player`'s own media query when
-       #42 moved the control into the bar — same rule, and now stated
-       where the element actually is.
+       is about room: five controls and a slider do not fit a 360px
+       bar, and the full-screen now-playing view is where seeking and
+       volume go on a phone. It moved from `audio-player`'s own media
+       query when #42 moved the control into the bar — same rule, and
+       now stated where the element actually is.
 
-       `.bottom-bar volume-control`, not the one in
-       `now-playing-view`: that view is the phone's transport and is
-       where a slider does belong. */
+       **This rule used to carry the platform argument too, and no
+       longer does** (#64). "The hardware keys own the volume" is not a
+       width: it is false of a narrow desktop window and true of an
+       Android tablet, which this selector gets backwards both ways.
+       The player answers it now — `SystemOwnsVolume` — and
+       `volume-control` renders nothing when it is true, at every
+       width and in both of its mount points. What is left here is the
+       question a stylesheet can actually answer. */
     .bottom-bar volume-control {
         display: none;
     }
+
+    /* The queue leaves the phone's bar (#59), because #55 made it a
+       screen with an entry in the back stack and Now Playing already
+       carries its own button for it. The route is the mini player's
+       art -> Now Playing -> the queue, which is the "reachable only
+       from Now Playing" this issue asks for.
+
+       This is allowed to remove a control only because the control is
+       still reachable: plan 018's matrix promises that no action is
+       ever unreachable at any supported size, and that promise is what
+       `phone-transport.spec.ts` asserts rather than the button count.
+
+       **`.bottom-bar #queue-button`, not `#queue-button`**, and that is
+       not decoration. The rule this overrides is written *nested*
+       inside `.bottom-bar`, so it builds to a descendant selector one
+       class more specific than it looks in the source -- and a bare
+       `#queue-button` here loses to it, media query or not. Being last
+       in the file is not enough when the thing above is more specific,
+       which is the same lesson as this section's own header one level
+       down: nesting adds specificity the source does not show, and the
+       failure is silent (the button simply stayed). */
+    .bottom-bar #queue-button {
+        display: none;
+    }
 }
 
 /* Out of the desktop grid entirely.  `job-band` renders nothing above
    600px anyway, but an in-flow grid child with no named area is
    auto-placed into a row of the shell -- the same trap the skip link is
-   absolutely positioned to avoid. */
-body job-band {
+   absolutely positioned to avoid.  `player-progress-line` (#58) is the
+   same element in the same position for the same reason: below 600px it
+   has a named row, and above it there is no border for it to sit on --
+   the desktop bar carries a real, interactive seek bar. */
+body job-band,
+body player-progress-line {
     display: none;
 }
 
@@ -574,3 +608,21 @@ body job-band {
         background-color: var(--yj-bg-elevated, #343a40);
     }
 }
+
+/* #58.  How far through the song we are, in its own grid row between
+   the two bars -- so the line is *on* the border rather than inside
+   either of them, and in flow rather than over it.  The row is `auto`
+   and the element renders nothing while no track is loaded, so it costs
+   no height at all until there is something to say.
+
+   **This block is below the `display: none` above and has to be**, for
+   the reason the band's rule is: a media query adds no specificity, so
+   `body player-progress-line { display: block }` written before that
+   rule loses to it at equal specificity and the line never appears at
+   any width.  Nothing fails; it is simply not there. */
+@media (max-width: 599px) {
+    body player-progress-line {
+        display: block;
+        grid-area: progress-line;
+    }
+}

frontend/index.html

@@ -81,6 +81,16 @@
             </button>
         </div>
     </footer>
+    <!-- How far through the song we are, on the border between the two
+         bars (#58). The shell's element rather than either bar's:
+         they are separate components stacked in this grid, so a line
+         on the border between them is a row of it, and neither one has
+         to reach into the other's box for two pixels. It renders
+         nothing above 600px and nothing with no track, is `aria-hidden`
+         (Now Playing's seek bar is what announces the position) and
+         takes no pointer events at all -- a thin line that sometimes
+         seeks is worse than one that never does. -->
+    <player-progress-line></player-progress-line>
     <!-- The phone's primary navigation, hidden above 600px by
          index.css.  Eager rather than a chunk, for the reason
          notification-host is: it is the only way to move around the

frontend/index.ts

@@ -21,6 +21,10 @@ import '@components/audio-player/audio-player.ts';
 // In the bar rather than inside `audio-player` since #42, so the shell
 // is what has to register it.
 import '@components/audio-player/volume-control/volume-control.ts';
+// The phone's progress line (#58), on the border between the mini
+// player and the tab bar. In the shell for the same reason the volume
+// is, and eager because it is part of the bottom bar's first paint.
+import '@components/audio-player/progress-line/progress-line.ts';
 import '@components/track-list/track-list.ts';
 import '@components/now-playing/now-playing.ts';
 import '@components/sidebar/app-sidebar.ts';

frontend/scripts/check-css-literals.mjs

@@ -23,97 +23,23 @@
  * as the literal contains an unterminated `/*`. Nothing else produces
  * that, and a legitimate literal cannot contain one.
  */
-import { readFileSync } from 'node:fs';
-import { globSync } from 'node:fs';
+import { globSync, readFileSync } from 'node:fs';
+
+import { taggedLiterals } from './css-literals.mjs';
 
 const TAGS = ['css', 'html', 'svg'];
 
-/**
- * Find the end of a template literal that starts at `start` (the index
- * of its opening backtick), respecting escapes and `${}` substitutions.
- * Returns the index of the closing backtick, or -1.
- */
-function endOfTemplate(src, start) {
-  let depth = 0;
-
-  for (let i = start + 1; i < src.length; i++) {
-    const c = src[i];
-
-    if (c === '\\') {
-      i++;
-      continue;
-    }
-
-    if (c === '$' && src[i + 1] === '{') {
-      depth++;
-      i++;
-      continue;
-    }
-
-    if (c === '}' && depth > 0) {
-      depth--;
-      continue;
-    }
-
-    if (c === '`' && depth === 0) return i;
-  }
-
-  return -1;
-}
-
-/** Strip `${...}` substitutions, which may legitimately contain anything. */
-function stripSubstitutions(text) {
-  let out = '';
-  let depth = 0;
-
-  for (let i = 0; i < text.length; i++) {
-    if (text[i] === '$' && text[i + 1] === '{') {
-      depth++;
-      i++;
-      continue;
-    }
-
-    if (text[i] === '}' && depth > 0) {
-      depth--;
-      continue;
-    }
-
-    if (depth === 0) out += text[i];
-  }
-
-  return out;
-}
-
-function lineOf(src, index) {
-  return src.slice(0, index).split('\n').length;
-}
-
 const files = globSync('src/**/*.ts', { cwd: process.cwd() });
 const problems = [];
 
 for (const file of files) {
   const src = readFileSync(file, 'utf8');
-  const tagPattern = new RegExp(`(^|[^\\w$.])(${TAGS.join('|')})\``, 'g');
 
-  let match;
-
-  while ((match = tagPattern.exec(src)) !== null) {
-    const open = match.index + match[0].length - 1;
-    const close = endOfTemplate(src, open);
-
-    if (close === -1) continue;
-
-    const body = stripSubstitutions(src.slice(open + 1, close));
+  for (const { tag, body, line } of taggedLiterals(src, TAGS)) {
     const opens = (body.match(/\/\*/g) ?? []).length;
     const closes = (body.match(/\*\//g) ?? []).length;
 
-    if (opens > closes) {
-      problems.push({
-        file,
-        line: lineOf(src, open),
-        tag: match[2],
-      });
-    }
+    if (opens > closes) problems.push({ file, line, tag });
   }
 }
 

frontend/scripts/check-css-nesting.mjs

@@ -0,0 +1,79 @@
+#!/usr/bin/env node
+/**
+ * Fail on a nested rule whose selector starts with an element name.
+ *
+ * See `css-nesting.mjs` for what the phone does with one. No tier here
+ * can see it: the component tier, the e2e tier and `make ui-visual` all
+ * run a current Chromium, where the rule applies normally, so the only
+ * report is a screenshot of the device — which is how the bottom bar's
+ * title came to have never truncated there.
+ *
+ * It covers `index.css` and the `css` literals in the components alike,
+ * because a shadow-root stylesheet is parsed by the same engine.
+ */
+import { globSync, readFileSync } from 'node:fs';
+
+import { taggedLiterals } from './css-literals.mjs';
+import { findBareNestedRules } from './css-nesting.mjs';
+
+const problems = [];
+
+// Every stylesheet, not `index.css` by name: the hook that runs this
+// fires on `frontend/**/*.{ts,css}`, so naming one file promises a
+// coverage the sweep does not deliver -- a second stylesheet would be
+// silently unswept while the hook still went green over it. There is
+// only `index.css` today, which is exactly when this is free to fix.
+const stylesheets = globSync('*.css', { cwd: process.cwd() });
+
+if (stylesheets.length === 0) {
+  console.error('css-nesting-check: no stylesheet matched *.css');
+  process.exit(1);
+}
+
+for (const file of stylesheets) {
+  for (const { line, selector } of findBareNestedRules(
+    readFileSync(file, 'utf8'),
+  )) {
+    problems.push({ file, line, selector });
+  }
+}
+
+const sources = globSync('src/**/*.ts', { cwd: process.cwd() });
+
+// A sweep over an empty glob passes, and this one is expected to find
+// nothing, so "it found nothing" has to mean it looked.
+if (sources.length === 0) {
+  console.error('css-nesting-check: no sources matched src/**/*.ts');
+  process.exit(1);
+}
+
+for (const file of sources) {
+  const src = readFileSync(file, 'utf8');
+
+  for (const literal of taggedLiterals(src, ['css'])) {
+    for (const { line, selector } of findBareNestedRules(literal.body)) {
+      problems.push({ file, line: literal.line + line - 1, selector });
+    }
+  }
+}
+
+if (problems.length > 0) {
+  for (const p of problems) {
+    console.error(
+      `${p.file}:${p.line}: nested rule "${p.selector.split('\n')[0]}" starts ` +
+        'with an element name — write it as "& ' +
+        `${p.selector.split('\n')[0]}"`,
+    );
+  }
+
+  console.error(
+    `\ncss-nesting-check: ${problems.length} problem(s). ` +
+      'Chrome 113 (the device) drops a nested rule that does not start ' +
+      'with a symbol; the leading & is valid in both syntaxes.',
+  );
+  process.exit(1);
+}
+
+console.log(
+  `css-nesting-check: ${stylesheets.length} stylesheet(s) + ${sources.length} files, no bare nested rules`,
+);

frontend/scripts/css-literals.mjs

@@ -0,0 +1,103 @@
+/**
+ * Finding the `css` tagged templates in a TypeScript source.
+ *
+ * Two checks read them — the unterminated-comment one and the nesting
+ * one — and a second scanner would be a second thing to keep in step
+ * with how a template literal actually ends.
+ */
+
+/**
+ * Find the end of a template literal that starts at `start` (the index
+ * of its opening backtick), respecting escapes and `${}` substitutions.
+ * Returns the index of the closing backtick, or -1.
+ */
+export function endOfTemplate(src, start) {
+  let depth = 0;
+
+  for (let i = start + 1; i < src.length; i++) {
+    const c = src[i];
+
+    if (c === '\\') {
+      i++;
+      continue;
+    }
+
+    if (c === '$' && src[i + 1] === '{') {
+      depth++;
+      i++;
+      continue;
+    }
+
+    if (c === '}' && depth > 0) {
+      depth--;
+      continue;
+    }
+
+    if (c === '`' && depth === 0) return i;
+  }
+
+  return -1;
+}
+
+/**
+ * Strip `${...}` substitutions, which may legitimately contain anything.
+ *
+ * Newlines inside them are kept, so a line number taken from the
+ * stripped text still names the right line of the file it came from.
+ */
+export function stripSubstitutions(text) {
+  let out = '';
+  let depth = 0;
+
+  for (let i = 0; i < text.length; i++) {
+    if (text[i] === '$' && text[i + 1] === '{') {
+      depth++;
+      i++;
+      continue;
+    }
+
+    if (text[i] === '}' && depth > 0) {
+      depth--;
+      continue;
+    }
+
+    if (depth === 0) out += text[i];
+    else if (text[i] === '\n') out += '\n';
+  }
+
+  return out;
+}
+
+/** The 1-based line number of `index` in `src`. */
+export function lineOf(src, index) {
+  return src.slice(0, index).split('\n').length;
+}
+
+/**
+ * Every tagged template literal in `src` whose tag is in `tags`.
+ *
+ * `body` has its substitutions stripped and `line` is the line its
+ * opening backtick sits on, so `line + (n - 1)` is the file line of the
+ * body's own line `n`.
+ */
+export function taggedLiterals(src, tags) {
+  const pattern = new RegExp(`(^|[^\\w$.])(${tags.join('|')})\``, 'g');
+  const found = [];
+
+  let match;
+
+  while ((match = pattern.exec(src)) !== null) {
+    const open = match.index + match[0].length - 1;
+    const close = endOfTemplate(src, open);
+
+    if (close === -1) continue;
+
+    found.push({
+      tag: match[2],
+      body: stripSubstitutions(src.slice(open + 1, close)),
+      line: lineOf(src, open),
+    });
+  }
+
+  return found;
+}

frontend/scripts/css-nesting.mjs

@@ -0,0 +1,119 @@
+/**
+ * A nested rule whose selector starts with an element name is silently
+ * dropped on the phone.
+ *
+ * The device renders in Chrome 113, which predates relaxed CSS nesting
+ * (Chrome 120): before that a nested selector had to start with
+ * something that could not be read as the beginning of a declaration,
+ * so `.bottom-bar { audio-player { … } }` is not a parse error anyone
+ * would notice — the inner rule simply does not exist, on the phone and
+ * only on the phone. Three were live in `index.css`, one of them the
+ * `text-overflow: ellipsis` on the bottom bar's title, which had
+ * therefore never truncated on the device.
+ *
+ * `& audio-player` is valid in both syntaxes, so no nested rule here
+ * has any reason to omit it.
+ *
+ * Two things the detection has to get right:
+ *
+ * - **A rule directly inside an at-rule is not nested.**
+ *   `@media (…) { bottom-nav { … } }` at the top level is an ordinary
+ *   rule and is fine — and it is the majority of the matches a regex
+ *   over the file would produce. What decides it is whether a *style*
+ *   rule is somewhere above, not what the immediate parent is: inside
+ *   `.bar { @media (…) { audio-player { … } } }` the inner rule is
+ *   nested, at-rule in between or not.
+ * - **A declaration is not a rule.** `background: url(…)` and any
+ *   string or comment can hold a brace, so this tracks them rather than
+ *   matching lines.
+ */
+
+/** Does this selector start with an identifier, rather than a symbol? */
+function startsWithIdent(selector) {
+  return /^[A-Za-z_\u00A0-\uFFFF]/.test(selector);
+}
+
+/**
+ * Every nested style rule in `css` whose selector starts with an
+ * element name, as `{ line, selector }` with a 1-based line.
+ */
+export function findBareNestedRules(css) {
+  const found = [];
+  /** The blocks we are inside, innermost last: 'style' or 'at'. */
+  const stack = [];
+  /** The text since the last `{`, `}` or `;` — a prelude, if a `{` follows. */
+  let prelude = '';
+  let preludeLine = 1;
+  let line = 1;
+
+  const startPrelude = () => {
+    prelude = '';
+    preludeLine = line;
+  };
+
+  for (let i = 0; i < css.length; i++) {
+    const c = css[i];
+
+    if (c === '\n') {
+      line++;
+      if (prelude.trim() === '') preludeLine = line;
+      prelude += c;
+      continue;
+    }
+
+    if (c === '/' && css[i + 1] === '*') {
+      const end = css.indexOf('*/', i + 2);
+      const comment = css.slice(i, end === -1 ? css.length : end + 2);
+
+      line += (comment.match(/\n/g) ?? []).length;
+      i += comment.length - 1;
+      if (prelude.trim() === '') preludeLine = line;
+      continue;
+    }
+
+    if (c === '"' || c === "'") {
+      let j = i + 1;
+
+      while (j < css.length && css[j] !== c) {
+        if (css[j] === '\\') j++;
+        j++;
+      }
+
+      prelude += css.slice(i, j + 1);
+      i = j;
+      continue;
+    }
+
+    if (c === '{') {
+      const selector = prelude.trim();
+      const kind = selector.startsWith('@') ? 'at' : 'style';
+
+      if (
+        kind === 'style' &&
+        stack.includes('style') &&
+        startsWithIdent(selector)
+      ) {
+        found.push({ line: preludeLine, selector });
+      }
+
+      stack.push(kind);
+      startPrelude();
+      continue;
+    }
+
+    if (c === '}') {
+      stack.pop();
+      startPrelude();
+      continue;
+    }
+
+    if (c === ';') {
+      startPrelude();
+      continue;
+    }
+
+    prelude += c;
+  }
+
+  return found;
+}

frontend/src/components/artists-view/artists-view.ts

@@ -26,14 +26,15 @@ import {
     contextMenuStyles,
     isContextMenuKey,
 } from '@utils/context-menu-controller.js';
-import type { ContextMenuHost } from '@utils/context-menu-controller.js';
+import type { ContextMenuHost, MenuTarget } from '@utils/context-menu-controller.js';
 import { FavoritesController } from '@store/controllers/favorites-controller';
 import { ViewLifecycleMixin } from '@utils/view-lifecycle';
 import { RovingGridController } from '@utils/roving-grid';
 
 import '@awesome.me/webawesome/dist/components/icon/icon.js';
 import '@awesome.me/webawesome/dist/components/popup/popup.js';
-import type WaPopup from '@awesome.me/webawesome/dist/components/popup/popup.js';
+import type { MenuSurface } from '../menu-surface/menu-surface';
+import '../menu-surface/menu-surface';
 import '@awesome.me/webawesome/dist/components/dropdown-item/dropdown-item.js';
 import '@components/playlist-picker/playlist-picker.js';
 import { dict, list } from '@utils/binding';
@@ -131,17 +132,17 @@ export class ArtistsView
     private contextMenuArtistId: number | null = null;
 
     @query('#context-menu')
-    private contextMenuPopup!: WaPopup;
+    private contextMenuPopup!: MenuSurface;
 
     @query('#playlist-submenu')
-    private playlistSubmenuPopup!: WaPopup;
+    private playlistSubmenuPopup!: MenuSurface;
 
-    getContextMenuPopup(): WaPopup | undefined {
+    getContextMenuPopup(): MenuTarget | undefined {
         return this.contextMenuPopup;
     }
 
     getPlaylistSubmenuPopup():
-        | WaPopup
+        | MenuTarget
         | undefined {
         return this.playlistSubmenuPopup;
     }
@@ -1336,11 +1337,8 @@ export class ArtistsView
 
     private renderContextMenu() {
         return html`
-            <wa-popup
+            <menu-surface
                 id="context-menu"
-                placement="bottom-start"
-                flip
-                shift
                 .active=${this.ctxMenu
                     .contextMenuOpen}
             >
@@ -1434,13 +1432,12 @@ export class ArtistsView
                           </div>
                       `
                     : nothing}
-            </wa-popup>
+            </menu-surface>
 
-            <wa-popup
+            <menu-surface
                 id="playlist-submenu"
+                label="Add to playlist"
                 placement="right-start"
-                flip
-                shift
                 .active=${this.ctxMenu
                     .playlistSubmenuOpen}
             >
@@ -1468,7 +1465,7 @@ export class ArtistsView
                           </div>
                       `
                     : nothing}
-            </wa-popup>
+            </menu-surface>
         `;
     }
 

frontend/src/components/audio-player/controls/player-controls.ts

@@ -1,22 +1,77 @@
-import { LitElement, html, css } from 'lit';
-import { customElement, state } from 'lit/decorators.js';
+import { LitElement, html, css, nothing } from 'lit';
+import { customElement, property, state } from 'lit/decorators.js';
 import '@awesome.me/webawesome/dist/components/icon/icon.js';
 import { PlayerController } from '@store/controllers/player-controller';
 import { queueStore } from '@store/queue-store';
 import type { RepeatMode } from '@store/queue-store';
 import { designTokens } from '../../../styles/tokens.css';
+import { PHONE_QUERY } from '../../../utils/breakpoints';
+
+/**
+ * The transport, in the two places it appears.
+ *
+ * **The context is a property and cannot be a media query**, which is
+ * the whole reason this exists (#56). Everywhere else in this app a
+ * component states what it drops at phone width itself, because a media
+ * query inside a shadow root is answered by the viewport and that is
+ * the honest signal. Here the two hosts want *different* answers at the
+ * *same* viewport: on a phone the bottom bar wants three controls sized
+ * for a thumb, and `now-playing-view` wants five, larger still. So the
+ * host says which context and the viewport says which size band, and
+ * neither one alone can express it.
+ *
+ * Measured at the reference device's 424x439 before this: every button
+ * here was **33x21px**, in both places, which is what #56 reports as
+ * "the most important thing in the mobile app and they are tiny".
+ */
+export type ControlsContext = 'bar' | 'full';
 
 @customElement('player-controls')
 export class PlayerControls extends LitElement {
   private player = new PlayerController(this);
   private unsubscribeQueue?: () => void;
 
+  /**
+   * Where these controls are drawn. `bar` is the bottom bar in both
+   * bands; `full` is the full-screen transport.
+   *
+   * Reflected so a spec can read it and so the stylesheet keys off one
+   * fact rather than a class the host has to remember to set.
+   */
+  @property({ type: String, reflect: true })
+  context: ControlsContext = 'bar';
+
   @state() private shuffleMode = false;
   @state() private repeatMode: RepeatMode = 'off';
 
+  /**
+   * Phone width, from `matchMedia` rather than from a media query,
+   * because what it decides is whether shuffle and repeat *exist* here
+   * — and a stylesheet can only decide whether they are painted.
+   * `job-band` and `search-trigger` are the same pattern for the same
+   * reason.
+   */
+  @state() private phone = false;
+
+  private media?: MediaQueryList;
+
+  private onMedia = (e: MediaQueryListEvent) => {
+    this.phone = e.matches;
+  };
+
+  /** Whether this is the phone's bottom bar, which carries three
+   *  controls rather than five. */
+  private get slim(): boolean {
+    return this.context === 'bar' && this.phone;
+  }
+
   override connectedCallback(): void {
     super.connectedCallback();
 
+    this.media = window.matchMedia(PHONE_QUERY);
+    this.phone = this.media.matches;
+    this.media.addEventListener('change', this.onMedia);
+
     const s = queueStore.getState();
     this.shuffleMode = s.shuffleMode;
     this.repeatMode = s.repeatMode;
@@ -37,6 +92,7 @@ export class PlayerControls extends LitElement {
   override disconnectedCallback(): void {
     super.disconnectedCallback();
     this.unsubscribeQueue?.();
+    this.media?.removeEventListener('change', this.onMedia);
   }
 
   static override styles = [designTokens, css`
@@ -58,6 +114,99 @@ export class PlayerControls extends LitElement {
       justify-content: center;
     }
 
+    /* ---------------------------------------------------------------
+       Sizes (#56).
+
+       44px is the floor everything here is sized to, and play/pause
+       alone goes above it -- "large play/pause, adequate prev/next" is
+       the Direction, and it is the one control the report calls "front
+       and centre".
+
+       They are stated as custom properties rather than on each button
+       so a context sets two numbers instead of five rules, and so the
+       icon scales with its target: a 44px box around a 16px glyph is a
+       big hit area that still looks tiny, which is half of what the
+       report is about.
+
+       **The desktop bar sets none of them and must not change at all.**
+       #56 is an Android issue; the desktop's buttons are 33x21 before
+       this and are 33x21 after it.
+
+       That is why the box rules take a zero fallback and the *font-size*
+       rules are scoped to the two contexts instead of sharing them. A
+       button does not inherit its font from its parent -- the UA
+       stylesheet gives it one -- so a generic font-size: inherit is
+       not the no-op it reads as: it moved the desktop's buttons from
+       33x21 to 36x24, silently, by taking them from the UA's 13.3px to
+       the shell's 16px. Measured before and after by stashing this
+       file, which is the only way that particular 3px shows up.
+       --------------------------------------------------------------- */
+    button {
+      min-width: var(--yj-control-target, 0);
+      min-height: var(--yj-control-target, 0);
+    }
+
+    button.play {
+      min-width: var(--yj-control-play-target, 0);
+      min-height: var(--yj-control-play-target, 0);
+    }
+
+    /* The phone's bottom bar: three controls, sized for a thumb.
+       Shuffle and repeat are not here -- see the render method, which
+       does not draw them rather than hiding them, because a control
+       that is display:none is still a thing the component claims to
+       have. They are on the full-screen view, which is one tap away
+       through the mini player's art (#59). */
+    @media (max-width: 599px) {
+      :host([context='bar']) {
+        --yj-control-target: 44px;
+        --yj-control-icon: 18px;
+        --yj-control-play-target: 56px;
+        --yj-control-play-icon: 24px;
+      }
+
+      :host([context='bar']) button {
+        font-size: var(--yj-control-icon);
+      }
+
+      :host([context='bar']) button.play {
+        font-size: var(--yj-control-play-icon);
+      }
+    }
+
+    /* The full-screen transport, at every width: this view *is* the
+       player, so the controls are the page rather than a strip of it. */
+    :host([context='full']) {
+      --yj-control-target: 44px;
+      --yj-control-icon: 20px;
+      --yj-control-play-target: 64px;
+      --yj-control-play-icon: 28px;
+    }
+
+    :host([context='full']) button {
+      font-size: var(--yj-control-icon);
+    }
+
+    :host([context='full']) button.play {
+      font-size: var(--yj-control-play-icon);
+    }
+
+    :host([context='full']) #player-control-buttons {
+      gap: 12px;
+    }
+
+    /* Secondary controls sit below the primary row rather than beside
+       it, which is the Direction's shape and is why this is a second
+       group in the DOM instead of a CSS order property: visual order
+       and focus order have to agree. */
+    .secondary {
+      display: flex;
+      justify-content: center;
+      align-items: center;
+      gap: 24px;
+      margin-top: 8px;
+    }
+
     button:hover {
       color: var(--yj-accent-text, #ffd43b);
     }
@@ -104,46 +253,107 @@ export class PlayerControls extends LitElement {
     queueStore.cycleRepeat();
   };
 
-  override render() {
-    const playOrPauseIcon = this.player.isPlaying ? 'pause' : 'play';
-    const playOrPauseHandler = this.player.isPlaying
-      ? this.handlePauseClick
-      : this.handlePlayClick;
+  /** Shuffle. Secondary: it changes how the queue behaves rather than
+   *  what is playing now. */
+  private renderShuffle() {
+    return html`
+      <button
+        class=${this.shuffleMode ? 'active' : ''}
+        aria-label="Shuffle"
+        aria-pressed=${this.shuffleMode}
+        @click=${this.handleShuffleClick}
+      >
+        <wa-icon name="shuffle"></wa-icon>
+      </button>
+    `;
+  }
 
-    const shuffleClass = this.shuffleMode ? 'active' : '';
+  /** Repeat, whose label spells the mode out because one icon covers
+   *  three states. */
+  private renderRepeat() {
     const repeatMode = this.repeatMode;
     const repeatClasses = [
       repeatMode !== 'off' ? 'active' : '',
       repeatMode === 'one' ? 'repeat-one' : '',
     ].filter(Boolean).join(' ');
 
+    return html`
+      <button
+        class=${repeatClasses}
+        aria-label=${`Repeat: ${repeatMode}`}
+        aria-pressed=${repeatMode !== 'off'}
+        @click=${this.handleRepeatClick}
+      >
+        <wa-icon name="repeat"></wa-icon>
+      </button>
+    `;
+  }
+
+  /** Previous, play/pause, next — the three that are always drawn, in
+   *  every context and at every width. Only play/pause takes the large
+   *  size: the Direction asks for "large play/pause, adequate
+   *  prev/next", and a row of identical squares says every action here
+   *  is equally likely, which is not true of play. */
+  private renderPrimary() {
+    const playOrPauseIcon = this.player.isPlaying ? 'pause' : 'play';
+    const playOrPauseHandler = this.player.isPlaying
+      ? this.handlePauseClick
+      : this.handlePlayClick;
+
+    return html`
+      <button
+        aria-label="Previous track"
+        @click=${this.handlePreviousClick}
+      >
+        <wa-icon name="backward-step"></wa-icon>
+      </button>
+      <button
+        class="play"
+        aria-label=${this.player.isPlaying ? 'Pause' : 'Play'}
+        @click="${playOrPauseHandler}"
+      >
+        <wa-icon name=${playOrPauseIcon}></wa-icon>
+      </button>
+      <button
+        aria-label="Next track"
+        @click=${this.handleNextClick}
+      >
+        <wa-icon name="forward-step"></wa-icon>
+      </button>
+    `;
+  }
+
+  /**
+   * Two arrangements, not two components.
+   *
+   * `bar` keeps the order it has always had — shuffle, prev, play,
+   * next, repeat, one row — so nothing about the desktop bar moves.
+   * `full` puts the primary three on their own row with the secondary
+   * pair beneath, which the Direction asks for.
+   *
+   * **The phone's bar draws three buttons rather than hiding two.** A
+   * `display: none` control is still in the component's shadow root,
+   * still in the accessibility tree's markup, and still something a
+   * `shadowAll('button')[4]` finds — so "the phone has three controls"
+   * would be true of the pixels and false of the element. They are
+   * reachable on the full-screen view, which the mini player's art
+   * opens, and through the global shortcuts.
+   */
+  override render() {
+    if (this.context === 'full') {
+      return html`
+        <div id="player-control-buttons">${this.renderPrimary()}</div>
+        <div class="secondary">
+          ${this.renderShuffle()}${this.renderRepeat()}
+        </div>
+      `;
+    }
+
     return html`
       <div id="player-control-buttons">
-        <button
-          class=${shuffleClass}
-          aria-label="Shuffle"
-          aria-pressed=${this.shuffleMode}
-          @click=${this.handleShuffleClick}
-        >
-          <wa-icon name="shuffle"></wa-icon>
-        </button>
-        <button aria-label="Previous track" @click=${this.handlePreviousClick}>
-          <wa-icon name="backward-step"></wa-icon>
-        </button>
-        <button aria-label=${this.player.isPlaying ? 'Pause' : 'Play'} @click="${playOrPauseHandler}">
-          <wa-icon name=${playOrPauseIcon}></wa-icon>
-        </button>
-        <button aria-label="Next track" @click=${this.handleNextClick}>
-          <wa-icon name="forward-step"></wa-icon>
-        </button>
-        <button
-          class=${repeatClasses}
-          aria-label=${`Repeat: ${repeatMode}`}
-          aria-pressed=${repeatMode !== 'off'}
-          @click=${this.handleRepeatClick}
-        >
-          <wa-icon name="repeat"></wa-icon>
-        </button>
+        ${this.slim ? nothing : this.renderShuffle()}
+        ${this.renderPrimary()}
+        ${this.slim ? nothing : this.renderRepeat()}
       </div>
     `;
   }

frontend/src/components/audio-player/progress-line/progress-line.ts

@@ -0,0 +1,204 @@
+import { LitElement, html, css, nothing } from 'lit';
+import { customElement, state } from 'lit/decorators.js';
+
+import { PlayerController } from '@store/controllers/player-controller';
+import { designTokens } from '../../../styles/tokens.css';
+import { PHONE_QUERY } from '../../../utils/breakpoints';
+
+/**
+ * How far through the song we are, on the border between the mini
+ * player and the tab bar (#58).
+ *
+ * The phone's bottom bar carries three controls and no seek bar — plan
+ * 016 B2 took it out, because 4px of height is not a thumb target and the
+ * full-screen `now-playing-view` is where seeking belongs. What went
+ * with it is the one thing a mini player is expected to say without
+ * being opened: how far through the song it is. This is that, and
+ * only that.
+ *
+ * Four things about it are load-bearing.
+ *
+ * **It is the shell's element, not either bar's.** The mini player and
+ * `<bottom-nav>` are separate components stacked in the shell's grid,
+ * so a line on the border between them is a row of the grid — either
+ * one drawing it means reaching into the other's box for two pixels.
+ *
+ * **It never counts.** The position is pushed at 1 Hz by the backend
+ * (`PlaybackPositionChanged`), and the interval here interpolates
+ * *between* those reports and is stopped and restarted by every one of
+ * them — the seek bar's rule, for the reason the seek bar has it: a
+ * local clock drifted 30 s away from the backend across four keyboard
+ * seeks. The `trackChangeId` and `seq` guards come along for the same
+ * reason: the store is a singleton, so a report about the previous
+ * track must not be adopted, and the same second reported twice still
+ * has to reset the interpolation.
+ *
+ * **It is not a control and cannot become one.** `aria-hidden` on the
+ * host and `pointer-events: none` throughout: the real progress is
+ * announced by the seek bar on Now Playing, and a 2px strip on the top
+ * edge of the tab bar that sometimes seeks is worse than one that
+ * never does. It is also where a thumb aiming at a tab lands.
+ *
+ * **It renders nothing above 600px**, from `matchMedia` rather than a
+ * media query, because that decides whether the element *exists* — and
+ * with it whether a 1 Hz interval runs for the life of every desktop
+ * session about a line nobody can see. `job-band`, `search-trigger`
+ * and `player-controls` are the same pattern for the same reason.
+ */
+
+/**
+ * The reporting cadence, matched. This is not the clock: it exists
+ * only so the line moves in the second between two reports, and its
+ * error is discarded by the next one rather than carried.
+ */
+const InterpolationIntervalMillis = 1000;
+
+@customElement('player-progress-line')
+export class PlayerProgressLine extends LitElement {
+    private player = new PlayerController(this);
+
+    /** Phone width. See the class comment: existence, not paint. */
+    @state() private phone = false;
+
+    /** Seconds into the track, from the last report plus interpolation. */
+    @state() private elapsed = 0;
+
+    private previousTrackChangeId = -1;
+
+    /** The sequence number of the last backend report applied. */
+    private previousPositionSeq = -1;
+
+    private timerID = -1;
+
+    private media?: MediaQueryList;
+
+    private onMedia = (e: MediaQueryListEvent) => {
+        this.phone = e.matches;
+    };
+
+    static override styles = [
+        designTokens,
+        css`
+            :host {
+                display: block;
+                /* Not a target, at any depth. */
+                pointer-events: none;
+            }
+
+            .track {
+                height: 2px;
+                background-color: var(--yj-bg-surface, #212529);
+            }
+
+            .fill {
+                height: 100%;
+                background-color: var(--yj-accent, #ffd43b);
+                /* scaleX off a full-width box rather than a width in
+                   percent, so the moving thing is a transform and the
+                   line costs no layout once a second. */
+                transform-origin: left center;
+            }
+        `,
+    ];
+
+    private get trackLength(): number {
+        return this.player.currentTrack?.trackLength ?? 0;
+    }
+
+    override connectedCallback(): void {
+        super.connectedCallback();
+
+        // Decorative in full: the seek bar on Now Playing is what
+        // announces the position, and this says the same thing without
+        // a name, a value or a way to act on it.
+        this.setAttribute('aria-hidden', 'true');
+
+        this.media = window.matchMedia(PHONE_QUERY);
+        this.phone = this.media.matches;
+        this.media.addEventListener('change', this.onMedia);
+    }
+
+    override disconnectedCallback(): void {
+        super.disconnectedCallback();
+        this.stopInterpolating();
+        this.media?.removeEventListener('change', this.onMedia);
+    }
+
+    override updated(): void {
+        // A track change resets the line, and `trackChangeId` is what
+        // reveals one when the same file plays twice in a row.
+        const currentChangeId = this.player.currentTrack?.trackChangeId ?? -1;
+
+        if (currentChangeId !== this.previousTrackChangeId) {
+            this.previousTrackChangeId = currentChangeId;
+            this.elapsed = this.player.currentTrack?.seekPosition ?? 0;
+            this.stopInterpolating();
+        }
+
+        // The backend's own position wins over anything counted here,
+        // and a report for a track that is no longer loaded is stale by
+        // definition.
+        const position = this.player.position;
+
+        if (
+            position &&
+            position.trackChangeId === currentChangeId &&
+            position.seq !== this.previousPositionSeq
+        ) {
+            this.previousPositionSeq = position.seq;
+            this.elapsed = position.positionSeconds;
+            this.stopInterpolating();
+        }
+
+        // One owner for the interval, as in `seek-bar`: everything that
+        // wants it started or stopped says so by changing state that
+        // brings us back here.
+        if (this.phone && this.player.isPlaying && currentChangeId !== -1) {
+            this.startInterpolating();
+        } else {
+            this.stopInterpolating();
+        }
+    }
+
+    private stopInterpolating(): void {
+        if (this.timerID !== -1) {
+            clearInterval(this.timerID);
+            this.timerID = -1;
+        }
+    }
+
+    private startInterpolating(): void {
+        if (this.timerID !== -1) {
+            return;
+        }
+
+        this.timerID = window.setInterval(() => {
+            if (this.elapsed < this.trackLength) {
+                this.elapsed += 1;
+            }
+        }, InterpolationIntervalMillis);
+    }
+
+    override render() {
+        // Nothing playing is nothing to say, and the grid row is `auto`
+        // so an empty render costs no height at all -- `job-band`'s
+        // rule one row down.
+        if (!this.phone || this.player.currentTrack === null) return nothing;
+
+        const length = this.trackLength;
+        const fraction =
+            length > 0 ? Math.min(1, Math.max(0, this.elapsed / length)) : 0;
+
+        return html`
+            <div class="track" data-testid="progress-line">
+                <div class="fill" style="transform: scaleX(${fraction})"></div>
+            </div>
+        `;
+    }
+}
+
+declare global {
+    interface HTMLElementTagNameMap {
+        'player-progress-line': PlayerProgressLine;
+    }
+}

frontend/src/components/audio-player/volume-control/volume-control.ts

@@ -1,4 +1,4 @@
-import { LitElement, html, css } from 'lit';
+import { LitElement, html, css, nothing } from 'lit';
 import { customElement, state } from 'lit/decorators.js';
 import '@awesome.me/webawesome/dist/components/icon/icon.js';
 import '@awesome.me/webawesome/dist/components/slider/slider.js';
@@ -27,6 +27,26 @@ export class VolumeControl extends LitElement {
   @state()
   private popup = volumeStyleStore.popup;
 
+  /**
+   * Whether there is a volume of ours to control at all (#64).
+   *
+   * The decision is made here rather than at either mount point,
+   * because there are two -- the bottom bar's copy lives in
+   * `index.html`, which has no module scope to make it conditional --
+   * and one of them is a control the shell cannot un-render. So the
+   * control answers for itself, and the bar and the phone's
+   * full-screen transport get the same answer without either knowing
+   * the question exists.
+   *
+   * It renders `nothing` *and* hides the host: an empty shadow root is
+   * what stops a positional or role query finding a button that cannot
+   * act, and `:host([hidden])` is what stops the element occupying a
+   * flex item's worth of the transport -- the `:host` display above
+   * outranks the UA's `[hidden]` rule, so it has to be said.
+   */
+  @state()
+  private available = volumeStyleStore.available;
+
   private unsubscribeStyle?: () => void;
 
   // Locally-tracked volume while the user is actively dragging or scrolling.
@@ -43,6 +63,13 @@ export class VolumeControl extends LitElement {
       align-items: center;
     }
 
+    /* See the available field. A gap is only drawn between boxes,
+       so a hidden host costs its parent nothing -- which is where the
+       29px this gives back to Now Playing comes from (#172). */
+    :host([hidden]) {
+      display: none;
+    }
+
     button {
       background: none;
       border: none;
@@ -154,12 +181,15 @@ export class VolumeControl extends LitElement {
 
     this.unsubscribeStyle = volumeStyleStore.subscribe(() => {
       this.popup = volumeStyleStore.popup;
+      this.setAvailable(volumeStyleStore.available);
 
       // Switching to the slider while the popup is open would leave the
       // document listener installed for a popup that no longer renders.
       if (!this.popup) this.closeSlider();
     });
 
+    this.setAvailable(volumeStyleStore.available);
+
     void volumeStyleStore.init();
   }
 
@@ -233,7 +263,25 @@ export class VolumeControl extends LitElement {
   // RENDER
   // ===================================================================
 
+  /**
+   * `hidden` is set imperatively rather than reflected from the state,
+   * because it has to be on the *host* and a `@state` does not reflect.
+   * It is the right attribute besides: it takes the element out of the
+   * accessibility tree as well as out of the layout.
+   */
+  private setAvailable(available: boolean) {
+    this.available = available;
+    this.hidden = !available;
+
+    // A popup left open when the control goes away would keep its
+    // document click listener installed for markup that no longer
+    // renders.
+    if (!available) this.closeSlider();
+  }
+
   override render() {
+    if (!this.available) return nothing;
+
     const muted = this.player.muted;
 
     // Inline, the icon is the mute toggle rather than a disclosure:

frontend/src/components/cover-grid/cover-grid.ts

@@ -23,7 +23,8 @@ import { gridColumnsFor, gridSpacingFor } from '@utils/grid-spacing';
 import { queueStore } from '@store/queue-store';
 import type { QueueSource } from '@store/queue-store';
 import '@awesome.me/webawesome/dist/components/popup/popup.js';
-import type WaPopup from '@awesome.me/webawesome/dist/components/popup/popup.js';
+import type { MenuSurface } from '../menu-surface/menu-surface';
+import '../menu-surface/menu-surface';
 import '@awesome.me/webawesome/dist/components/dropdown-item/dropdown-item.js';
 import '@awesome.me/webawesome/dist/components/icon/icon.js';
 import '@components/playlist-picker/playlist-picker.js';
@@ -51,7 +52,7 @@ import {
     ContextMenuController,
     isContextMenuKey,
 } from '@utils/context-menu-controller.js';
-import type { ContextMenuHost } from '@utils/context-menu-controller.js';
+import type { ContextMenuHost, MenuTarget } from '@utils/context-menu-controller.js';
 import { FavoritesController } from '@store/controllers/favorites-controller';
 import { creditLink, exploreLinkStyles } from '../../utils/explore-link';
 import { creditStore } from '@store/credit-store';
@@ -415,17 +416,17 @@ export class CoverGrid
     splitIndex = 0;
 
     @query('#context-menu')
-    private contextMenuPopup!: WaPopup;
+    private contextMenuPopup!: MenuSurface;
 
     @query('#playlist-submenu')
-    private playlistSubmenuPopup!: WaPopup;
+    private playlistSubmenuPopup!: MenuSurface;
 
     // ContextMenuHost interface.
-    getContextMenuPopup(): WaPopup | undefined {
+    getContextMenuPopup(): MenuTarget | undefined {
         return this.contextMenuPopup;
     }
 
-    getPlaylistSubmenuPopup(): WaPopup | undefined {
+    getPlaylistSubmenuPopup(): MenuTarget | undefined {
         return this.playlistSubmenuPopup;
     }
 
@@ -2087,11 +2088,8 @@ export class CoverGrid
         const { ctxMenu } = this;
 
         return html`
-            <wa-popup
+            <menu-surface
                 id="context-menu"
-                placement="bottom-start"
-                flip
-                shift
                 .active=${ctxMenu.contextMenuOpen}
             >
                 ${ctxMenu.contextMenuOpen
@@ -2204,13 +2202,12 @@ export class CoverGrid
                           </div>
                       `
                 : nothing}
-            </wa-popup>
+            </menu-surface>
 
-            <wa-popup
+            <menu-surface
                 id="playlist-submenu"
+                label="Add to playlist"
                 placement="right-start"
-                flip
-                shift
                 .active=${ctxMenu.playlistSubmenuOpen}
             >
                 ${ctxMenu.playlistSubmenuOpen
@@ -2232,7 +2229,7 @@ export class CoverGrid
                           </div>
                       `
                 : nothing}
-            </wa-popup>
+            </menu-surface>
 
             <track-details></track-details>
         `;

frontend/src/components/explore-album-details/explore-album-details.ts

@@ -49,9 +49,11 @@ import {
     contextMenuStyles,
     isContextMenuKey,
 } from '@utils/context-menu-controller.js';
-import type { ContextMenuHost } from '@utils/context-menu-controller.js';
+import type { ContextMenuHost, MenuTarget } from '@utils/context-menu-controller.js';
 import '@awesome.me/webawesome/dist/components/popup/popup.js';
 import type WaPopup from '@awesome.me/webawesome/dist/components/popup/popup.js';
+import type { MenuSurface } from '../menu-surface/menu-surface';
+import '../menu-surface/menu-surface';
 import '@awesome.me/webawesome/dist/components/dropdown-item/dropdown-item.js';
 import { dictByName } from '@utils/binding';
 import type { TrackDetails } from '@components/track-details/track-details.js';
@@ -327,7 +329,7 @@ export class ExploreAlbumDetails extends LitElement implements ContextMenuHost {
     @state() private ctxMenuTrack: MBTrack | null = null;
 
     @query('#track-context-menu')
-    private contextMenuPopup!: WaPopup;
+    private contextMenuPopup!: MenuSurface;
 
     @query('#playlist-submenu')
     private playlistSubmenuPopup?: WaPopup;
@@ -337,11 +339,11 @@ export class ExploreAlbumDetails extends LitElement implements ContextMenuHost {
 
     // -- ContextMenuHost interface --
 
-    getContextMenuPopup(): WaPopup | undefined {
+    getContextMenuPopup(): MenuTarget | undefined {
         return this.contextMenuPopup;
     }
 
-    getPlaylistSubmenuPopup(): WaPopup | undefined {
+    getPlaylistSubmenuPopup(): MenuTarget | undefined {
         return this.playlistSubmenuPopup;
     }
 
@@ -890,6 +892,67 @@ export class ExploreAlbumDetails extends LitElement implements ContextMenuHost {
             .track-row .track-request {
                 flex-shrink: 0;
             }
+
+            /* ── The phone (#66) ──
+             *
+             * **This block is last on purpose**, for index.css's
+             * reason: a media query adds no specificity, so a rule
+             * written above the plain one it overrides loses to it and
+             * every declaration here is silently dead.
+             *
+             * Two faults, one shape. The page is a fixed header over a
+             * scrolling tracklist — the desktop arrangement — so at the
+             * reference device's 424x439 the header owned 253 of the
+             * panel's 318px and the tracklist scrolled inside the 64px
+             * that were left. And the header's flex row squeezed
+             * .album-info to 112px, so the title drew as one ellipsised
+             * glyph and two of the album's three primary actions were
+             * clipped by the host's own overflow: Shuffle album ended
+             * at x=443 in a 424px box, unreachable by any gesture.
+             *
+             * .album-info carries min-width: 0 and was shrinking as
+             * asked, so another one is not the fix — the row has to
+             * stack, or the info column has nothing to be wide with.
+             *
+             * The scroller moves to the host and .content stops being
+             * one, which is what makes the header scroll away; the
+             * tracklist is plain DOM rather than a virtualizer, so
+             * nothing inside wants a scroll window of its own. */
+            @media (max-width: 599px) {
+                :host {
+                    overflow-y: auto;
+                }
+
+                .album-header {
+                    flex-direction: column;
+                    align-items: flex-start;
+                    gap: 12px;
+                    padding: 12px 16px;
+                }
+
+                /* Stacked, the art is the whole of the header's width
+                 * budget and its 200px square is 45% of the reference
+                 * device's height. It is still what identifies the
+                 * album, so it shrinks rather than going. */
+                .cover-art-container {
+                    width: 140px;
+                    height: 140px;
+                }
+
+                /* A column flex item takes its content's width from
+                 * align-items: flex-start above, which would leave the
+                 * actions wrapping inside a box narrower than the row
+                 * they now have to themselves. */
+                .album-info {
+                    align-self: stretch;
+                }
+
+                .content {
+                    flex: 0 0 auto;
+                    overflow-y: visible;
+                    padding: 16px 16px 24px;
+                }
+            }
         `,
     ];
 
@@ -3781,11 +3844,8 @@ export class ExploreAlbumDetails extends LitElement implements ContextMenuHost {
         const track = this.ctxMenuTrack;
 
         return html`
-            <wa-popup
+            <menu-surface
                 id="track-context-menu"
-                placement="bottom-start"
-                flip
-                shift
                 .active=${this.ctxMenu.contextMenuOpen}
             >
                 ${this.ctxMenu.contextMenuOpen && track
@@ -3846,13 +3906,12 @@ export class ExploreAlbumDetails extends LitElement implements ContextMenuHost {
                           </div>
                       `
                     : nothing}
-            </wa-popup>
+            </menu-surface>
 
-            <wa-popup
+            <menu-surface
                 id="playlist-submenu"
+                label="Add to playlist"
                 placement="right-start"
-                flip
-                shift
                 .active=${this.ctxMenu.playlistSubmenuOpen}
             >
                 ${this.ctxMenu.playlistSubmenuOpen
@@ -3869,7 +3928,7 @@ export class ExploreAlbumDetails extends LitElement implements ContextMenuHost {
                           </div>
                       `
                     : nothing}
-            </wa-popup>
+            </menu-surface>
         `;
     }
 }

frontend/src/components/explore-artist-details/explore-artist-details.ts

@@ -61,9 +61,11 @@ import {
     contextMenuStyles,
     isContextMenuKey,
 } from '@utils/context-menu-controller.js';
-import type { ContextMenuHost } from '@utils/context-menu-controller.js';
+import type { ContextMenuHost, MenuTarget } from '@utils/context-menu-controller.js';
 import '@awesome.me/webawesome/dist/components/popup/popup.js';
 import type WaPopup from '@awesome.me/webawesome/dist/components/popup/popup.js';
+import type { MenuSurface } from '../menu-surface/menu-surface';
+import '../menu-surface/menu-surface';
 import '@awesome.me/webawesome/dist/components/dropdown-item/dropdown-item.js';
 import { dict, dictByName } from '@utils/binding';
 import type { TrackDetails } from '@components/track-details/track-details.js';
@@ -215,7 +217,7 @@ export class ExploreArtistDetails extends LitElement implements ContextMenuHost
     @state() private ctxMenuTarget: ContextMenuTarget | null = null;
 
     @query('#context-menu')
-    private contextMenuPopup!: WaPopup;
+    private contextMenuPopup!: MenuSurface;
 
     @query('#playlist-submenu')
     private playlistSubmenuPopup?: WaPopup;
@@ -233,11 +235,11 @@ export class ExploreArtistDetails extends LitElement implements ContextMenuHost
 
     // -- ContextMenuHost interface --
 
-    getContextMenuPopup(): WaPopup | undefined {
+    getContextMenuPopup(): MenuTarget | undefined {
         return this.contextMenuPopup;
     }
 
-    getPlaylistSubmenuPopup(): WaPopup | undefined {
+    getPlaylistSubmenuPopup(): MenuTarget | undefined {
         return this.playlistSubmenuPopup;
     }
 
@@ -2621,11 +2623,8 @@ export class ExploreArtistDetails extends LitElement implements ContextMenuHost
         const target = this.ctxMenuTarget;
 
         return html`
-            <wa-popup
+            <menu-surface
                 id="context-menu"
-                placement="bottom-start"
-                flip
-                shift
                 .active=${this.ctxMenu.contextMenuOpen}
             >
                 ${this.ctxMenu.contextMenuOpen && target
@@ -2643,13 +2642,12 @@ export class ExploreArtistDetails extends LitElement implements ContextMenuHost
                           </div>
                       `
                     : nothing}
-            </wa-popup>
+            </menu-surface>
 
-            <wa-popup
+            <menu-surface
                 id="playlist-submenu"
+                label="Add to playlist"
                 placement="right-start"
-                flip
-                shift
                 .active=${this.ctxMenu.playlistSubmenuOpen}
             >
                 ${this.ctxMenu.playlistSubmenuOpen
@@ -2666,7 +2664,7 @@ export class ExploreArtistDetails extends LitElement implements ContextMenuHost
                           </div>
                       `
                     : nothing}
-            </wa-popup>
+            </menu-surface>
         `;
     }
 

frontend/src/components/explore-view/explore-view.ts

@@ -37,9 +37,11 @@ import {
     contextMenuStyles,
     isContextMenuKey,
 } from '@utils/context-menu-controller.js';
-import type { ContextMenuHost } from '@utils/context-menu-controller.js';
+import type { ContextMenuHost, MenuTarget } from '@utils/context-menu-controller.js';
 import '@awesome.me/webawesome/dist/components/popup/popup.js';
 import type WaPopup from '@awesome.me/webawesome/dist/components/popup/popup.js';
+import type { MenuSurface } from '../menu-surface/menu-surface';
+import '../menu-surface/menu-surface';
 import '@awesome.me/webawesome/dist/components/dropdown-item/dropdown-item.js';
 import { dict, dictByName } from '@utils/binding';
 import { ICON_QUEUE } from '@utils/icon-language';
@@ -206,13 +208,13 @@ export class ExploreView extends ViewLifecycleMixin(LitElement) implements Conte
     @state() private ctxMenuTarget: ExploreMenuTarget | null = null;
 
     @litQuery('#explore-context-menu')
-    private contextMenuPopup!: WaPopup;
+    private contextMenuPopup!: MenuSurface;
 
     // -- ContextMenuHost interface --
     // No playlist submenu — same reason as the album/artist detail
     // pages: every action here resolves its one file lazily.
 
-    getContextMenuPopup(): WaPopup | undefined {
+    getContextMenuPopup(): MenuTarget | undefined {
         return this.contextMenuPopup;
     }
 
@@ -1341,11 +1343,8 @@ export class ExploreView extends ViewLifecycleMixin(LitElement) implements Conte
         const owned = Boolean(target?.localId);
 
         return html`
-            <wa-popup
+            <menu-surface
                 id="explore-context-menu"
-                placement="bottom-start"
-                flip
-                shift
                 .active=${this.ctxMenu.contextMenuOpen}
             >
                 ${this.ctxMenu.contextMenuOpen && target
@@ -1374,7 +1373,7 @@ export class ExploreView extends ViewLifecycleMixin(LitElement) implements Conte
                           </div>
                       `
                     : nothing}
-            </wa-popup>
+            </menu-surface>
         `;
     }
 

frontend/src/components/genres-view/genres-view.ts

@@ -24,14 +24,15 @@ import {
     contextMenuStyles,
     isContextMenuKey,
 } from '@utils/context-menu-controller.js';
-import type { ContextMenuHost } from '@utils/context-menu-controller.js';
+import type { ContextMenuHost, MenuTarget } from '@utils/context-menu-controller.js';
 import { FavoritesController } from '@store/controllers/favorites-controller';
 import { ViewLifecycleMixin } from '@utils/view-lifecycle';
 import { RovingGridController } from '@utils/roving-grid';
 
 import '@awesome.me/webawesome/dist/components/icon/icon.js';
 import '@awesome.me/webawesome/dist/components/popup/popup.js';
-import type WaPopup from '@awesome.me/webawesome/dist/components/popup/popup.js';
+import type { MenuSurface } from '../menu-surface/menu-surface';
+import '../menu-surface/menu-surface';
 import '@awesome.me/webawesome/dist/components/dropdown-item/dropdown-item.js';
 import '@components/playlist-picker/playlist-picker.js';
 import { dictByName } from '@utils/binding';
@@ -137,19 +138,19 @@ export class GenresView
     private contextMenuGenreName: string | null = null;
 
     @query('#context-menu')
-    private contextMenuPopup!: WaPopup;
+    private contextMenuPopup!: MenuSurface;
 
     @query('#playlist-submenu')
-    private playlistSubmenuPopup!: WaPopup;
+    private playlistSubmenuPopup!: MenuSurface;
 
     // ----- ContextMenuHost interface -----
 
-    getContextMenuPopup(): WaPopup | undefined {
+    getContextMenuPopup(): MenuTarget | undefined {
         return this.contextMenuPopup;
     }
 
     getPlaylistSubmenuPopup():
-        | WaPopup
+        | MenuTarget
         | undefined {
         return this.playlistSubmenuPopup;
     }
@@ -1176,11 +1177,8 @@ export class GenresView
 
     private renderContextMenu() {
         return html`
-            <wa-popup
+            <menu-surface
                 id="context-menu"
-                placement="bottom-start"
-                flip
-                shift
                 .active=${this.ctxMenu
                     .contextMenuOpen}
             >
@@ -1284,13 +1282,12 @@ export class GenresView
                           </div>
                       `
                     : nothing}
-            </wa-popup>
+            </menu-surface>
 
-            <wa-popup
+            <menu-surface
                 id="playlist-submenu"
+                label="Add to playlist"
                 placement="right-start"
-                flip
-                shift
                 .active=${this.ctxMenu
                     .playlistSubmenuOpen}
             >
@@ -1318,7 +1315,7 @@ export class GenresView
                           </div>
                       `
                     : nothing}
-            </wa-popup>
+            </menu-surface>
         `;
     }
 

frontend/src/components/menu-surface/menu-surface.ts

@@ -0,0 +1,318 @@
+/**
+ * Where a context menu is drawn: a popup on a desktop, a bottom sheet
+ * on a phone (#60).
+ *
+ * Every context menu in this app is a `.context-menu-panel` inside a
+ * `<wa-popup>` anchored to the touch point, driven by
+ * `ContextMenuController`. On the reference device that is structurally
+ * broken, and the failure was measured on the hardware rather than
+ * inferred:
+ *
+ * - Chrome 113 has **no Popover API** (`popover` is Chrome 114), so
+ *   `wa-popup` takes its own documented fallback and positions with
+ *   `strategy: "fixed"` instead of the top layer. Measured on the
+ *   device: `HTMLElement.prototype.hasOwnProperty('popover')` is false
+ *   and the popup's computed `position` is `fixed`.
+ * - `index.css` puts `contain: layout style paint` on `.main-panel`,
+ *   the ancestor of every view. Paint containment **clips** fixed
+ *   descendants. Measured: `.main-panel` computes `contain: content`
+ *   and spans 0-318 of a 439px viewport, while the open menu spans
+ *   191-401 — so 83px of it, three of its seven items, is cut off.
+ *
+ * A `<dialog>` fixes it by construction rather than by styling, because
+ * `showModal()` is Chrome 37 and uses the real top layer. **That was
+ * measured too, and it needed to be**: every other dialog in this app
+ * is mounted in `index.html`, *outside* `.main-panel`, so "dialogs are
+ * fine" was not evidence about a dialog opened from inside a view. A
+ * probe dialog appended to `track-list`'s shadow root paints to y=439,
+ * over the mini player and the tab bar, with the contained ancestor
+ * still there.
+ *
+ * Four things about this component are load-bearing.
+ *
+ * **It is one element with two presentations, not two components.**
+ * The host keeps rendering exactly the panel it rendered before and
+ * slots it into whichever surface is up, so the twelve call sites
+ * changed one tag name each and nothing else — no second item model, no
+ * second keyboard model, and `ContextMenuController` still drives
+ * `.active` and `.anchor` as if it were talking to a `wa-popup`.
+ *
+ * **Which surface exists is `matchMedia`, not a media query.** The
+ * decision is whether a `<dialog>` is in the tree at all, which is
+ * `job-band` and `player-controls`' rule: a `display: none` surface is
+ * still in the shadow root and still something a positional or by-role
+ * query finds.
+ *
+ * **The sheet has to un-do the UA stylesheet to be full-bleed.**
+ * A native `<dialog>` carries `max-width: calc(100% - 6px - 2em)` and
+ * `margin: auto`, which on the device produced a 354px panel floating
+ * in the middle of a 424px screen. `max-width: none` and explicit
+ * margins are what make it a sheet rather than a small centred box.
+ * The *positioning* needs no such care: a top-layer dialog's containing
+ * block is the viewport even with a paint-contained ancestor, which is
+ * why `bottom: 0` reaches y=439 and not the main panel's 318.
+ *
+ * **Dismissal has to travel back.** `wa-dialog` closes itself on
+ * Escape, which would otherwise leave the controller's
+ * `contextMenuOpen` true and the menu unopenable until something else
+ * cleared it. `menu-dismiss` is that signal, and the controller listens
+ * for it on the document beside the click and contextmenu listeners it
+ * already has.
+ */
+import { LitElement, css, html } from 'lit';
+import { customElement, property, query, state } from 'lit/decorators.js';
+import '@awesome.me/webawesome/dist/components/popup/popup.js';
+import '@awesome.me/webawesome/dist/components/dialog/dialog.js';
+import type WaPopup from '@awesome.me/webawesome/dist/components/popup/popup.js';
+
+import { PHONE_QUERY } from '@utils/breakpoints';
+import { nameDialogsIn } from '@utils/name-dialog';
+
+/** The event a surface dispatches when it closed itself. */
+export const MENU_DISMISS_EVENT = 'menu-dismiss';
+
+/**
+ * The event a surface dispatches once it has finished showing.
+ *
+ * Only the sheet sends it, and only because `wa-dialog` moves focus to
+ * itself on the frame after `showModal()` -- see `MenuKeyboard.refocus`
+ * for why waiting longer is not the fix.
+ */
+export const MENU_SHOWN_EVENT = 'menu-shown';
+
+/**
+ * A `wa-popup` anchor: a real element or a virtual one.
+ *
+ * `undefined` rather than `null` for "not set yet", because that is
+ * what `wa-popup`'s own property accepts — this surface hands the value
+ * straight through and must not widen it.
+ */
+type MenuAnchor = WaPopup['anchor'] | undefined;
+
+/** A `wa-dialog`, as much of it as this file needs. */
+type DialogEl = HTMLElement & { open: boolean };
+
+@customElement('menu-surface')
+export class MenuSurface extends LitElement {
+    /** Whether the menu is showing. Set by `ContextMenuController`. */
+    @property({ type: Boolean }) active = false;
+
+    /**
+     * Where the popup hangs from. Ignored in sheet mode, which is
+     * anchored to the bottom of the screen rather than to the touch
+     * point — that is the whole point of a sheet.
+     */
+    @property({ attribute: false }) anchor: MenuAnchor = undefined;
+
+    /**
+     * `wa-popup`'s placement, defaulted because all twelve call sites
+     * passed the same one. Kept as a property so a future menu that
+     * wants another does not have to reach past this component.
+     */
+    @property() placement = 'bottom-start';
+
+    /**
+     * What to call the sheet, for a surface whose content is not a
+     * `.context-menu-panel` with an `aria-label` of its own -- the
+     * playlist submenu, whose content is a `playlist-picker`.
+     */
+    @property() label = '';
+
+    @state() private sheet = false;
+
+    @query('wa-popup') private popup?: WaPopup;
+
+    @query('wa-dialog') private dialog?: DialogEl;
+
+    private phoneQuery?: MediaQueryList;
+
+    static override styles = css`
+        :host {
+            display: contents;
+        }
+
+        wa-popup {
+            z-index: 200;
+        }
+
+        /* The sheet. A native dialog's UA stylesheet centres it and
+           caps its width, which on the device drew a 354px box in the
+           middle of a 424px screen — so all four of these are undoing
+           that rather than decorating. */
+        wa-dialog::part(dialog) {
+            margin: auto auto 0 auto;
+            max-width: none;
+            max-height: 85vh;
+            width: 100%;
+            border-radius: 12px 12px 0 0;
+            background: var(--yj-bg-elevated, #343a40);
+            padding: 0;
+        }
+
+        /* **A long menu scrolls; it does not hang off the bottom.**
+           Measured on the device at 80vh: seven 48px rows plus the grip
+           came to 364px against a 351px dialog, so the last row's
+           bottom was at y=452 on a 439px screen -- the one row a
+           destructive action is most likely to be. The cap has to stay
+           (a sheet covering the whole screen is a page, not a sheet),
+           so the body is what gives. */
+        wa-dialog::part(body) {
+            padding: 0;
+            overflow-y: auto;
+        }
+
+        /* A sheet is dragged at with a thumb, so it says where its top
+           edge is. Decorative: the panel below it carries the actions. */
+        .grip {
+            width: 36px;
+            height: 4px;
+            margin: 8px auto 4px;
+            border-radius: 2px;
+            background: var(--yj-text-tertiary, #888);
+        }
+    `;
+
+    override connectedCallback(): void {
+        super.connectedCallback();
+
+        // Looked up here rather than at module load, so a test can
+        // install its own matchMedia before the element is created.
+        this.phoneQuery = window.matchMedia?.(PHONE_QUERY);
+        this.sheet = this.phoneQuery?.matches ?? false;
+        this.phoneQuery?.addEventListener('change', this.onPhoneChange);
+    }
+
+    override disconnectedCallback(): void {
+        super.disconnectedCallback();
+        this.phoneQuery?.removeEventListener('change', this.onPhoneChange);
+    }
+
+    private onPhoneChange = (e: MediaQueryListEvent): void => {
+        this.sheet = e.matches;
+    };
+
+    /**
+     * Re-run the popup's positioning.
+     *
+     * Forwarded rather than dropped because `page-header` calls it when
+     * it opens the overflow menu: the popup is rendered before the
+     * button it anchors to has settled. A sheet has nothing to
+     * reposition -- it is anchored to the bottom of the screen -- so
+     * there it is deliberately a no-op rather than an error.
+     */
+    reposition(): void {
+        this.popup?.reposition();
+    }
+
+    /**
+     * The panel the host slotted in. It is light DOM here and stays in
+     * the host's shadow root, which is what keeps the host's own
+     * `contextMenuStyles` applying to it in both presentations.
+     */
+    private get panel(): HTMLElement | null {
+        return this.querySelector('.context-menu-panel');
+    }
+
+    override updated(): void {
+        const panel = this.panel;
+
+        // The sheet's rows are bigger, and that rule lives in the one
+        // stylesheet every call site already includes rather than in
+        // twelve places. The attribute is how it knows.
+        if (panel) panel.toggleAttribute('data-sheet', this.sheet);
+
+        if (this.sheet) {
+            this.syncSheet(panel);
+
+            return;
+        }
+
+        if (this.popup) {
+            if (this.anchor) this.popup.anchor = this.anchor;
+
+            this.popup.active = this.active;
+        }
+    }
+
+    private syncSheet(panel: HTMLElement | null): void {
+        const dialog = this.dialog;
+
+        if (!dialog) return;
+
+        // The dialog is named after the menu it contains, so no call
+        // site has to say the same thing twice: the panel already
+        // carries `role="menu"` and an `aria-label` naming what it acts
+        // on. `without-header` renders no heading, which is
+        // `name-dialog`'s documented `aria-label` path.
+        const label = panel?.getAttribute('aria-label') || this.label;
+
+        if (label) dialog.setAttribute('label', label);
+
+        nameDialogsIn(this.shadowRoot);
+
+        if (dialog.open !== this.active) dialog.open = this.active;
+    }
+
+    /**
+     * `wa-dialog` closed itself — Escape, or its own close button.
+     * The controller owns `contextMenuOpen`, so it has to hear about
+     * it or the menu is left open in state and shut on screen.
+     */
+    private onDialogShown = (): void => {
+        if (!this.active) return;
+
+        this.dispatchEvent(
+            new CustomEvent(MENU_SHOWN_EVENT, {
+                bubbles: true,
+                composed: true,
+            }),
+        );
+    };
+
+    private onDialogHide = (): void => {
+        if (!this.active) return;
+
+        this.dispatchEvent(
+            new CustomEvent(MENU_DISMISS_EVENT, {
+                bubbles: true,
+                composed: true,
+            }),
+        );
+    };
+
+    override render() {
+        if (this.sheet) {
+            // **The anchor stays out of the sheet.** One call site --
+            // `page-header`'s overflow menu -- slots its own trigger
+            // button as the thing the popup hangs from, and a sheet
+            // hangs from the bottom of the screen instead. Rendering
+            // that slot outside the dialog is what keeps the button on
+            // the page rather than inside the surface it opens.
+            return html`
+                <slot name="anchor"></slot>
+                <wa-dialog
+                    without-header
+                    data-testid="menu-sheet"
+                    @wa-after-show=${this.onDialogShown}
+                    @wa-hide=${this.onDialogHide}
+                >
+                    <div class="grip"></div>
+                    <slot></slot>
+                </wa-dialog>
+            `;
+        }
+
+        return html`
+            <wa-popup placement=${this.placement} flip shift>
+                <slot name="anchor" slot="anchor"></slot>
+                <slot></slot>
+            </wa-popup>
+        `;
+    }
+}
+
+declare global {
+    interface HTMLElementTagNameMap {
+        'menu-surface': MenuSurface;
+    }
+}

frontend/src/components/now-playing-view/now-playing-view.ts

@@ -117,8 +117,27 @@ export class NowPlayingView extends LitElement {
         .art .placeholder {
             /* Square, and never taller than the room left over: the
                art is the one thing here that would happily push the
-               transport off the bottom of a short phone. */
+               transport off the bottom of a short phone.
+
+               **max-height is what actually keeps that promise**, and
+               it was missing. With a definite width and
+               a 1:1 aspect-ratio the height is *derived from the width*
+               and is bounded by nothing: at the reference device's
+               424x439 that is a 263px square (60vh) in a box with far
+               less than 263px left, so the art overflowed its own
+               centred flex item and drew over the header above and the
+               title below it. The comment claimed this was handled;
+               60vh is a bound on the *viewport*, not on the room left
+               over, and those differ by however much chrome is above
+               and below.
+
+               Pre-existing -- screenshotted on main -- and made acute
+               by #56, which gives the transport 95px more than it had.
+               Found by reading a screenshot, which is the only tier
+               that can see it: nothing fails, nothing overflows the
+               *shell*, and every control is still hittable. */
             width: min(100%, 60vh);
+            max-height: 100%;
             aspect-ratio: 1;
             object-fit: cover;
             border-radius: 12px;
@@ -317,7 +336,19 @@ export class NowPlayingView extends LitElement {
 
             <div class="transport">
                 <seek-bar></seek-bar>
-                <player-controls></player-controls>
+                <!-- context="full": this view *is* the player, so the
+                     transport is the page rather than a strip of it --
+                     primary controls large, shuffle and repeat beneath
+                     at normal size (#56). It is a property rather than
+                     a media query because the bottom bar wants a
+                     different answer at this same viewport. -->
+                <player-controls context="full"></player-controls>
+                <!-- Rendered unconditionally and absent on its own
+                     terms where the device owns the volume (#64): the
+                     control asks the player, not this view and not the
+                     viewport. A hidden host draws no gap, so that is
+                     29px of a 439px screen back to the album art
+                     (#172). -->
                 <volume-control></volume-control>
             </div>
         `;

frontend/src/components/now-playing/now-playing.ts

@@ -215,6 +215,17 @@ export class NowPlaying extends LitElement {
         outline: 2px solid var(--yj-accent, #ffd43b);
         outline-offset: 2px;
       }
+
+      /* The favourite is one of the three controls #59 keeps on the
+         phone's bar, and it was the **smallest control in the app**:
+         measured at 424x439, 18x14px, against the 48x48 art beside it.
+         Zero padding around an icon-sized glyph is a reasonable mouse
+         target and is not a thumb target at all. */
+      .fav-btn {
+        min-width: 44px;
+        min-height: 44px;
+        font-size: var(--yj-icon-md);
+      }
     }
 
     .cover-preview-panel {
@@ -446,8 +457,30 @@ export class NowPlaying extends LitElement {
             return html`
         <div class="sr-only" role="status" aria-live="polite">${announcement}</div>
         <div class="now-playing">
-          <div class="cover-art">
-            <div class="cover-placeholder"><wa-icon name="music"></wa-icon></div>
+          <!-- **The way to Now Playing does not depend on what is
+               playing.** This branch used to render the placeholder
+               with no button on it, so on a phone there was no route to
+               the full-screen view while nothing was loaded -- and once
+               #59 took the queue button off the bar, that made the
+               queue itself unreachable, because Now Playing is where it
+               is reached from. The queue is persisted across restarts,
+               so "a queue with tracks in it and nothing playing" is an
+               ordinary state to launch into, not a corner.
+
+               Plan 018's matrix promises no action is unreachable at
+               any supported size, and the promise is what makes #59
+               allowed to remove a control at all. -->
+          <div class="cover-art-wrapper">
+            <button
+              type="button"
+              class="expand"
+              data-testid="open-now-playing"
+              aria-label="Open now playing"
+              @click=${this.openNowPlaying}
+            ></button>
+            <div class="cover-art">
+              <div class="cover-placeholder"><wa-icon name="music"></wa-icon></div>
+            </div>
           </div>
         </div>
         <div

frontend/src/components/page-header/page-header.ts

@@ -1,9 +1,9 @@
 import { LitElement, html, css, nothing } from 'lit';
 import { customElement, property, query, state } from 'lit/decorators.js';
 import '@awesome.me/webawesome/dist/components/icon/icon.js';
-import '@awesome.me/webawesome/dist/components/popup/popup.js';
 import '@awesome.me/webawesome/dist/components/dropdown-item/dropdown-item.js';
-import type WaPopup from '@awesome.me/webawesome/dist/components/popup/popup.js';
+import type { MenuSurface } from '../menu-surface/menu-surface';
+import '../menu-surface/menu-surface';
 
 import { designTokens } from '../../styles/tokens.css';
 import {
@@ -183,8 +183,8 @@ export class PageHeader extends LitElement {
     @query('#page-header-overflow')
     private menuPanel?: HTMLElement;
 
-    @query('wa-popup')
-    private popup?: WaPopup;
+    @query('menu-surface')
+    private popup?: MenuSurface;
 
     private menuKeyboard = new MenuKeyboard(() => this.closeMenu());
 
@@ -418,7 +418,7 @@ export class PageHeader extends LitElement {
                 outline-offset: -1px;
             }
 
-            wa-popup {
+            menu-surface {
                 z-index: 200;
             }
 
@@ -670,10 +670,17 @@ export class PageHeader extends LitElement {
         return html`
             <div class="actions">
                 ${this.actions.map((a) => this.renderActionButton(a))}
-                <wa-popup
+                <!-- A sheet below 600px, like every other menu in the
+                     app (#60). The clipping that issue is about does
+                     not bite here — this one opens downward from the
+                     top of a full-height view, so it has somewhere to
+                     go even without top-layer promotion — but the touch
+                     targets do: on a phone *every* action of a page
+                     that overflows lives in here, at wa-dropdown-item
+                     defaults. One surface, so there is no second
+                     answer to what a menu looks like. -->
+                <menu-surface
                     placement="bottom-end"
-                    flip
-                    shift
                     .active=${this.menuOpen}
                 >
                     <button
@@ -711,7 +718,7 @@ export class PageHeader extends LitElement {
                             `,
                         )}
                     </div>
-                </wa-popup>
+                </menu-surface>
             </div>
         `;
     }

frontend/src/components/playlist-details/playlist-details.ts

@@ -7,7 +7,8 @@ import {
 } from 'lit/decorators.js';
 import '@awesome.me/webawesome/dist/components/icon/icon.js';
 import '@awesome.me/webawesome/dist/components/popup/popup.js';
-import type WaPopup from '@awesome.me/webawesome/dist/components/popup/popup.js';
+import type { MenuSurface } from '../menu-surface/menu-surface';
+import '../menu-surface/menu-surface';
 import '@awesome.me/webawesome/dist/components/dropdown-item/dropdown-item.js';
 import '@lit-labs/virtualizer';
 import type { LitVirtualizer } from '@lit-labs/virtualizer';
@@ -35,7 +36,7 @@ import {
     contextMenuStyles,
     isContextMenuKey,
 } from '@utils/context-menu-controller.js';
-import type { ContextMenuHost } from '@utils/context-menu-controller.js';
+import type { ContextMenuHost, MenuTarget } from '@utils/context-menu-controller.js';
 import { focusRovingRow, nextRovingIndex } from '@utils/roving-rows';
 import { FavoritesController } from '@store/controllers/favorites-controller';
 import { notificationStore } from '@store/notification-store';
@@ -145,10 +146,10 @@ export class PlaylistDetails
     private dragImageEl: HTMLElement | null = null;
 
     @query('#context-menu')
-    private contextMenuPopup!: WaPopup;
+    private contextMenuPopup!: MenuSurface;
 
     @query('#playlist-submenu')
-    private playlistSubmenuPopup!: WaPopup;
+    private playlistSubmenuPopup!: MenuSurface;
 
     @query('track-details')
     private trackDetailsDialog!: TrackDetails;
@@ -163,11 +164,11 @@ export class PlaylistDetails
     // ContextMenuHost interface
     // =================================================================
 
-    getContextMenuPopup(): WaPopup | undefined {
+    getContextMenuPopup(): MenuTarget | undefined {
         return this.contextMenuPopup;
     }
 
-    getPlaylistSubmenuPopup(): WaPopup | undefined {
+    getPlaylistSubmenuPopup(): MenuTarget | undefined {
         return this.playlistSubmenuPopup;
     }
 
@@ -1617,11 +1618,8 @@ export class PlaylistDetails
 
     private renderContextMenu() {
         return html`
-            <wa-popup
+            <menu-surface
                 id="context-menu"
-                placement="bottom-start"
-                flip
-                shift
                 .active=${this.ctxMenu
                     .contextMenuOpen}
             >
@@ -1783,13 +1781,12 @@ export class PlaylistDetails
                               </div>
                           `
                     : nothing}
-            </wa-popup>
+            </menu-surface>
 
-            <wa-popup
+            <menu-surface
                 id="playlist-submenu"
+                label="Add to playlist"
                 placement="right-start"
-                flip
-                shift
                 .active=${this.ctxMenu
                     .playlistSubmenuOpen}
             >
@@ -1816,7 +1813,7 @@ export class PlaylistDetails
                           </div>
                       `
                     : nothing}
-            </wa-popup>
+            </menu-surface>
         `;
     }
 }

frontend/src/components/playlist-view/playlist-view.ts

@@ -2,7 +2,9 @@ import { LitElement, html, css, nothing } from 'lit';
 import { customElement, state, query } from 'lit/decorators.js';
 import '@awesome.me/webawesome/dist/components/icon/icon.js';
 import '@awesome.me/webawesome/dist/components/popup/popup.js';
-import type WaPopup from '@awesome.me/webawesome/dist/components/popup/popup.js';
+
+import type { MenuSurface } from '../menu-surface/menu-surface';
+import '../menu-surface/menu-surface';
 import '@awesome.me/webawesome/dist/components/dropdown-item/dropdown-item.js';
 
 import {
@@ -140,7 +142,7 @@ export class PlaylistView extends ViewLifecycleMixin(LitElement) {
     private pendingDropPaths: string[] = [];
 
     @query('#playlist-context-menu')
-    private playlistContextMenuPopup!: WaPopup;
+    private playlistContextMenuPopup!: MenuSurface;
 
     @query('duplicate-tracks-dialog')
     private duplicateDialog!: DuplicateTracksDialog;
@@ -1059,7 +1061,7 @@ export class PlaylistView extends ViewLifecycleMixin(LitElement) {
         );
     }
 
-    private closePlaylistContextMenu() {
+    private closePlaylistContextMenu = () => {
         if (!this.playlistContextMenuOpen) return;
 
         this.menuKeyboard.close();
@@ -1072,7 +1074,7 @@ export class PlaylistView extends ViewLifecycleMixin(LitElement) {
         if (popup) {
             popup.active = false;
         }
-    }
+    };
 
     private async onPlaylistContextAction(
         action: string,
@@ -1500,13 +1502,11 @@ export class PlaylistView extends ViewLifecycleMixin(LitElement) {
                   </div>`
                 : this.renderPlaylistList()}
 
-            <wa-popup
+            <menu-surface
                 id="playlist-context-menu"
-                placement="bottom-start"
-                flip
-                shift
                 .active=${this
                     .playlistContextMenuOpen}
+                @menu-dismiss=${this.closePlaylistContextMenu}
             >
                 ${this.playlistContextMenuOpen
                     ? html`
@@ -1564,7 +1564,7 @@ export class PlaylistView extends ViewLifecycleMixin(LitElement) {
                           </div>
                       `
                     : nothing}
-            </wa-popup>
+            </menu-surface>
 
             <duplicate-tracks-dialog
                 @playlist-action-complete=${() =>

frontend/src/components/queue-panel/queue-panel.ts

@@ -9,7 +9,8 @@ import {
 } from 'lit/decorators.js';
 import '@awesome.me/webawesome/dist/components/icon/icon.js';
 import '@awesome.me/webawesome/dist/components/popup/popup.js';
-import type WaPopup from '@awesome.me/webawesome/dist/components/popup/popup.js';
+import type { MenuSurface } from '../menu-surface/menu-surface';
+import '../menu-surface/menu-surface';
 import '@awesome.me/webawesome/dist/components/dropdown-item/dropdown-item.js';
 import { QueueController } from '@store/controllers/queue-controller';
 import { creditStore } from '@store/credit-store';
@@ -34,7 +35,7 @@ import {
     contextMenuStyles,
     isContextMenuKey,
 } from '@utils/context-menu-controller.js';
-import type { ContextMenuHost } from '@utils/context-menu-controller.js';
+import type { ContextMenuHost, MenuTarget } from '@utils/context-menu-controller.js';
 import { focusRovingRow, nextRovingIndex } from '@utils/roving-rows';
 import { FavoritesController } from '@store/controllers/favorites-controller';
 import {
@@ -140,13 +141,13 @@ export class QueuePanel
     private delegationAttached = false;
 
     @query('#add-to-playlist-popup')
-    private addToPlaylistPopup!: WaPopup;
+    private addToPlaylistPopup!: MenuSurface;
 
     @query('#context-menu')
-    private contextMenuPopup!: WaPopup;
+    private contextMenuPopup!: MenuSurface;
 
     @query('#playlist-submenu')
-    private playlistSubmenuPopup!: WaPopup;
+    private playlistSubmenuPopup!: MenuSurface;
 
     /** Unsubscribes the credit-arrival repaint. */
     private creditsUnsub?: () => void;
@@ -305,11 +306,11 @@ export class QueuePanel
     // ContextMenuHost interface
     // =================================================================
 
-    getContextMenuPopup(): WaPopup | undefined {
+    getContextMenuPopup(): MenuTarget | undefined {
         return this.contextMenuPopup;
     }
 
-    getPlaylistSubmenuPopup(): WaPopup | undefined {
+    getPlaylistSubmenuPopup(): MenuTarget | undefined {
         return this.playlistSubmenuPopup;
     }
 
@@ -1092,7 +1093,7 @@ export class QueuePanel
         }
     }
 
-    private closePlaylistPicker() {
+    private closePlaylistPicker = () => {
         if (!this.playlistPickerOpen) return;
 
         this.playlistPickerOpen = false;
@@ -1102,7 +1103,7 @@ export class QueuePanel
         if (popup) {
             popup.active = false;
         }
-    }
+    };
 
     private onPlaylistActionComplete = () => {
         this.closePlaylistPicker();
@@ -2042,9 +2043,11 @@ export class QueuePanel
                     </div>
                 </div>
 
-                <wa-popup
+                <menu-surface
                     id="add-to-playlist-popup"
+                    label="Add to playlist"
                     placement="bottom-end"
+                    @menu-dismiss=${this.closePlaylistPicker}
                     .active=${this.playlistPickerOpen}
                 >
                     ${this.playlistPickerOpen
@@ -2060,7 +2063,7 @@ export class QueuePanel
                               ></playlist-picker>
                           `
                         : nothing}
-                </wa-popup>
+                </menu-surface>
 
                 <div
                     class="list-area"
@@ -2103,11 +2106,8 @@ export class QueuePanel
                 </div>
             </div>
 
-            <wa-popup
+            <menu-surface
                 id="context-menu"
-                placement="bottom-start"
-                flip
-                shift
                 .active=${this.ctxMenu.contextMenuOpen}
             >
                 ${this.ctxMenu.contextMenuOpen
@@ -2195,13 +2195,12 @@ export class QueuePanel
                           </div>
                       `
                     : nothing}
-            </wa-popup>
+            </menu-surface>
 
-            <wa-popup
+            <menu-surface
                 id="playlist-submenu"
+                label="Add to playlist"
                 placement="right-start"
-                flip
-                shift
                 .active=${this.ctxMenu.playlistSubmenuOpen}
             >
                 ${this.ctxMenu.playlistSubmenuOpen &&
@@ -2224,7 +2223,7 @@ export class QueuePanel
                           </div>
                       `
                     : nothing}
-            </wa-popup>
+            </menu-surface>
 
             <track-details></track-details>
         `;

frontend/src/components/smart-playlist-details/smart-playlist-details.ts

@@ -26,7 +26,7 @@ import {
     contextMenuStyles,
     isContextMenuKey,
 } from '@utils/context-menu-controller.js';
-import type { ContextMenuHost } from '@utils/context-menu-controller.js';
+import type { ContextMenuHost, MenuTarget } from '@utils/context-menu-controller.js';
 import { focusRovingRow, nextRovingIndex } from '@utils/roving-rows';
 import { FavoritesController } from '@store/controllers/favorites-controller';
 import {
@@ -40,7 +40,8 @@ import {
 } from '@utils/drag-image';
 import '@awesome.me/webawesome/dist/components/icon/icon.js';
 import '@awesome.me/webawesome/dist/components/popup/popup.js';
-import type WaPopup from '@awesome.me/webawesome/dist/components/popup/popup.js';
+import type { MenuSurface } from '../menu-surface/menu-surface';
+import '../menu-surface/menu-surface';
 import '@awesome.me/webawesome/dist/components/dropdown-item/dropdown-item.js';
 import '@lit-labs/virtualizer';
 import type { LitVirtualizer } from '@lit-labs/virtualizer';
@@ -176,10 +177,10 @@ export class SmartPlaylistDetails
     private dragImageEl: HTMLElement | null = null;
 
     @query('#context-menu')
-    private contextMenuPopup!: WaPopup;
+    private contextMenuPopup!: MenuSurface;
 
     @query('#playlist-submenu')
-    private playlistSubmenuPopup!: WaPopup;
+    private playlistSubmenuPopup!: MenuSurface;
 
     @query('track-details')
     private trackDetailsDialog!: TrackDetails;
@@ -188,11 +189,11 @@ export class SmartPlaylistDetails
     // ContextMenuHost interface
     // =================================================================
 
-    getContextMenuPopup(): WaPopup | undefined {
+    getContextMenuPopup(): MenuTarget | undefined {
         return this.contextMenuPopup;
     }
 
-    getPlaylistSubmenuPopup(): WaPopup | undefined {
+    getPlaylistSubmenuPopup(): MenuTarget | undefined {
         return this.playlistSubmenuPopup;
     }
 
@@ -1465,11 +1466,8 @@ export class SmartPlaylistDetails
 
     private renderContextMenu() {
         return html`
-            <wa-popup
+            <menu-surface
                 id="context-menu"
-                placement="bottom-start"
-                flip
-                shift
                 .active=${this.ctxMenu.contextMenuOpen}
             >
                 ${this.ctxMenu.contextMenuOpen
@@ -1583,13 +1581,12 @@ export class SmartPlaylistDetails
                           </div>
                       `
                     : nothing}
-            </wa-popup>
+            </menu-surface>
 
-            <wa-popup
+            <menu-surface
                 id="playlist-submenu"
+                label="Add to playlist"
                 placement="right-start"
-                flip
-                shift
                 .active=${this.ctxMenu
                     .playlistSubmenuOpen}
             >
@@ -1616,7 +1613,7 @@ export class SmartPlaylistDetails
                           </div>
                       `
                     : nothing}
-            </wa-popup>
+            </menu-surface>
         `;
     }
 }

frontend/src/components/track-list/track-list.ts

@@ -18,7 +18,7 @@ import {
     isContextMenuKey,
 } from '@utils/context-menu-controller.js';
 
-import type { ContextMenuHost } from '@utils/context-menu-controller.js';
+import type { ContextMenuHost, MenuTarget } from '@utils/context-menu-controller.js';
 import { PlayerController } from '@store/controllers/player-controller';
 import { SearchController } from '@store/controllers/search-controller';
 import '@components/page-header/page-header';
@@ -63,7 +63,8 @@ import type {
 } from '@lit-labs/virtualizer';
 import { flow } from '@lit-labs/virtualizer/layouts/flow.js';
 import '@awesome.me/webawesome/dist/components/popup/popup.js';
-import type WaPopup from '@awesome.me/webawesome/dist/components/popup/popup.js';
+import type { MenuSurface } from '../menu-surface/menu-surface';
+import '../menu-surface/menu-surface';
 import '@awesome.me/webawesome/dist/components/dropdown-item/dropdown-item.js';
 import '@awesome.me/webawesome/dist/components/icon/icon.js';
 import { describeError } from '@utils/describe-error';
@@ -231,18 +232,18 @@ export class TrackList
     private tracks: library.Track[] = [];
 
     @query('#context-menu')
-    private contextMenuPopup!: WaPopup;
+    private contextMenuPopup!: MenuSurface;
 
     @query('#playlist-submenu')
-    private playlistSubmenuPopup!: WaPopup;
+    private playlistSubmenuPopup!: MenuSurface;
 
     // -- ContextMenuHost interface --
 
-    getContextMenuPopup(): WaPopup | undefined {
+    getContextMenuPopup(): MenuTarget | undefined {
         return this.contextMenuPopup;
     }
 
-    getPlaylistSubmenuPopup(): WaPopup | undefined {
+    getPlaylistSubmenuPopup(): MenuTarget | undefined {
         return this.playlistSubmenuPopup;
     }
 
@@ -2323,11 +2324,8 @@ export class TrackList
             </div>
           `}
 
-      <wa-popup
+      <menu-surface
         id="context-menu"
-        placement="bottom-start"
-        flip
-        shift
         .active=${this.ctxMenu.contextMenuOpen}
       >
         ${this.ctxMenu.contextMenuOpen
@@ -2413,13 +2411,12 @@ export class TrackList
               </div>
             `
                 : nothing}
-      </wa-popup>
+      </menu-surface>
 
-      <wa-popup
+      <menu-surface
         id="playlist-submenu"
+                label="Add to playlist"
         placement="right-start"
-        flip
-        shift
         .active=${this.ctxMenu.playlistSubmenuOpen}
       >
         ${this.ctxMenu.playlistSubmenuOpen && this.selection.hasSelection
@@ -2437,7 +2434,7 @@ export class TrackList
               </div>
             `
                 : nothing}
-      </wa-popup>
+      </menu-surface>
 
       <track-details></track-details>
     `;

frontend/src/store/volume-style-store.ts

@@ -1,5 +1,6 @@
 import { EventsOn } from '@runtime/runtime';
 import { GetPopupVolume } from '@go/config/config.js';
+import { SystemOwnsVolume } from '@go/player/player.js';
 import { Events } from '../events';
 
 type Subscriber = () => void;
@@ -28,10 +29,37 @@ type Subscriber = () => void;
  * becomes one. An install that has chosen the popup sees it swap once
  * on load, which is the cheaper of the two wrong first frames: the
  * inline slider occupies the space the popup's button would have.
+ *
+ * **`available` is the question one step earlier — whether there is a
+ * volume of ours to draw at all (#64).** On Android the hardware keys
+ * are the volume control and the backend pins its own level at
+ * maximum, so a slider here would move nothing.
+ *
+ * It is asked of the *player* rather than of the viewport, and that is
+ * the whole design decision. Every other stand-down rule in this app
+ * is a width, because a width is what a browser can answer and what
+ * every tier can test — but this one is a property of the build. Keyed
+ * on width instead, an Android tablet at 600px or more would draw the
+ * bottom bar's slider over a pinned level: a control that cannot act,
+ * which `library-status-indicator` settled is worse than none.
+ *
+ * It lives beside `popup` because both answer "what presentation does
+ * the volume control get", both readers are the same two components,
+ * and "none" is a presentation. A second store would be a second
+ * subscription in the same `connectedCallback` saying the same thing.
+ *
+ * The initial value is `true` on the same first-frame rule: there is a
+ * volume on every platform but one, and the platform that pins it sees
+ * the control once at boot and never again in the session — the answer
+ * cannot change while the app runs, so by the time the lazily-mounted
+ * now-playing view exists it has long been settled by the bar's own
+ * copy.
  */
 class VolumeStyleStore {
     private value = false;
 
+    private hasVolume = true;
+
     private loaded = false;
 
     private subscribers = new Set<Subscriber>();
@@ -47,13 +75,21 @@ class VolumeStyleStore {
         return this.value;
     }
 
+    /**
+     * Whether this app has a volume of its own to control. False where
+     * the device owns it; see the class comment.
+     */
+    get available(): boolean {
+        return this.hasVolume;
+    }
+
     /** Reads the setting once. Safe to call from every mount. */
     async init(): Promise<void> {
         if (this.loaded) return;
 
         this.loaded = true;
 
-        await this.refresh();
+        await Promise.all([this.refreshAvailability(), this.refresh()]);
     }
 
     subscribe(fn: Subscriber): () => void {
@@ -77,6 +113,28 @@ class VolumeStyleStore {
         }
     }
 
+    /**
+     * Asked once, not on `GeneralConfigChanged`: this is a property of
+     * the platform the binary was built for and cannot change while
+     * the app is running.
+     */
+    private async refreshAvailability(): Promise<void> {
+        try {
+            const owned = await SystemOwnsVolume();
+
+            if (owned === !this.hasVolume) return;
+
+            this.hasVolume = !owned;
+            this.notify();
+        } catch (err) {
+            // The control renders, which is the answer on every
+            // platform but one and is the recoverable way to be wrong:
+            // a working control nobody needs, rather than a missing one
+            // somebody does.
+            console.error('failed to ask who owns the volume', err);
+        }
+    }
+
     private notify(): void {
         for (const fn of this.subscribers) fn();
     }

frontend/src/utils/context-menu-controller.ts

@@ -5,7 +5,20 @@ import type {
 } from 'lit';
 import type WaPopup from '@awesome.me/webawesome/dist/components/popup/popup.js';
 
+/**
+ * What this controller needs of a surface: something it can switch on
+ * and point at. Both `wa-popup` and `menu-surface` satisfy it.
+ */
+export type MenuTarget = HTMLElement & {
+    active: boolean;
+    anchor?: WaPopup['anchor'];
+};
+
 import { registerViewAware } from './view-lifecycle';
+import {
+    MENU_DISMISS_EVENT,
+    MENU_SHOWN_EVENT,
+} from '../components/menu-surface/menu-surface';
 
 /**
  * Host interface for components using the ContextMenuController.
@@ -17,10 +30,18 @@ export interface ContextMenuHost
     extends ReactiveControllerHost {
     updateComplete: Promise<boolean>;
     shadowRoot: ShadowRoot | null;
-    /** Return the main context-menu popup element. */
-    getContextMenuPopup(): WaPopup | undefined;
-    /** Return the playlist submenu popup element. */
-    getPlaylistSubmenuPopup(): WaPopup | undefined;
+    /**
+     * Return the main context-menu surface.
+     *
+     * `MenuSurface` since #60, which is a `wa-popup` above 600px and a
+     * bottom sheet below it. The type is the narrow shape this
+     * controller drives rather than either element, so a host that
+     * still renders a bare `wa-popup` — the playlist submenu does —
+     * satisfies it unchanged.
+     */
+    getContextMenuPopup(): MenuTarget | undefined;
+    /** Return the playlist submenu surface. */
+    getPlaylistSubmenuPopup(): MenuTarget | undefined;
     /**
      * Called when the context menu is closed by an
      * outside click/contextmenu/mousedown.  Components
@@ -33,6 +54,15 @@ export interface ContextMenuHost
 /** Submenu close delay in milliseconds. */
 const SUBMENU_CLOSE_DELAY = 150;
 
+/**
+ * How long to keep trying to put focus on a menu's first item.
+ *
+ * Long enough to outlast `wa-dialog`'s show animation, which ends by
+ * focusing the dialog; short enough that a menu which genuinely has no
+ * items stops rather than spinning for the life of the page.
+ */
+const FOCUS_RETRY_BUDGET_MS = 500;
+
 /** A menu item, focusable and clickable. Web Awesome sets `role` itself. */
 type MenuItem = HTMLElement & { active?: boolean; disabled?: boolean };
 
@@ -73,6 +103,30 @@ export class MenuKeyboard {
         void this.focusFirstItem(panel);
     }
 
+    /**
+     * Take focus back, for a surface that finished showing after we
+     * had already placed it.
+     *
+     * `wa-dialog` focuses `[autofocus]` or *itself* on the animation
+     * frame after `showModal()`, and it cannot see our first menu item
+     * to prefer it: the panel is slotted through `menu-surface`, so the
+     * dialog's own `querySelector` stops at the `<slot>`. Retrying on a
+     * longer budget does not fix this either -- the first attempt
+     * *succeeds*, and the steal happens afterwards. Measured on the
+     * device: the sheet opened with focus on the `<dialog>` and every
+     * arrow key went nowhere.
+     *
+     * So the surface says when it has settled and this re-asserts. It
+     * is a no-op for a menu that is closed or that already has focus.
+     */
+    refocus(): void {
+        const panel = this.panel;
+
+        if (!panel || panel.contains(deepActiveElement())) return;
+
+        void this.focusFirstItem(panel);
+    }
+
     /**
      * Focus the first item, once the items are items.
      *
@@ -91,11 +145,24 @@ export class MenuKeyboard {
 
         await Promise.all(candidates.map((el) => el.updateComplete ?? null));
 
-        // …and once the popup has positioned itself. `wa-popup` places the
+        // …and once the surface has shown itself. `wa-popup` places the
         // panel on an animation frame, and `focus()` on a not-yet-shown
         // element is a silent no-op — which looks identical to a menu
         // that opened and refused to take focus.
-        for (let attempt = 0; attempt < 3; attempt++) {
+        //
+        // **The budget is time, not frames, because #60 gave this a
+        // second kind of surface.** Three frames was enough for a
+        // popup; a `wa-dialog` runs a show *animation* and moves focus
+        // to the dialog itself when it finishes, which lands after
+        // those frames and takes the focus back. Measured on the
+        // device: the sheet opened with `document.activeElement` on the
+        // `<dialog>`, so every arrow key went nowhere. Retrying to a
+        // deadline is `roving-grid`'s rule for the same reason — the
+        // thing being waited for is another component's animation, not
+        // a fixed number of paints.
+        const deadline = Date.now() + FOCUS_RETRY_BUDGET_MS;
+
+        while (Date.now() < deadline) {
             // Bail if the menu closed while we waited.
             if (this.panel !== panel) return;
 
@@ -259,6 +326,20 @@ export class ContextMenuController
     /** Bound close handler for document events. */
     private closeHandler = () => this.close();
 
+    /**
+     * A surface finished showing; see `MenuKeyboard.refocus`.
+     *
+     * **Not while the submenu is up.** Both surfaces send this, and the
+     * submenu's sheet opens *over* the main one -- so re-asserting
+     * focus on the main panel's first item would snatch it straight
+     * back out of the playlist picker the user just opened.
+     */
+    private shownHandler = () => {
+        if (this.contextMenuOpen && !this.playlistSubmenuOpen) {
+            this.keyboard.refocus();
+        }
+    };
+
     /** Bound mousedown handler for outside-click detection. */
     private mousedownCloseHandler = (
         e: MouseEvent,
@@ -325,12 +406,28 @@ export class ContextMenuController
             'mousedown',
             this.mousedownCloseHandler,
         );
+        document.addEventListener(
+            MENU_DISMISS_EVENT,
+            this.closeHandler,
+        );
+        document.addEventListener(
+            MENU_SHOWN_EVENT,
+            this.shownHandler,
+        );
     }
 
     private detach(): void {
         if (!this.listening) return;
 
         this.listening = false;
+        document.removeEventListener(
+            MENU_DISMISS_EVENT,
+            this.closeHandler,
+        );
+        document.removeEventListener(
+            MENU_SHOWN_EVENT,
+            this.shownHandler,
+        );
         document.removeEventListener(
             'click',
             this.closeHandler,
@@ -550,6 +647,48 @@ export const contextMenuStyles = css`
         z-index: 200;
     }
 
+    /* ---------------------------------------------------------------
+       The sheet (#60).
+
+       menu-surface puts data-sheet on the panel when it is drawn
+       as a bottom sheet, and these rules are here rather than in that
+       component because the panel is the *host's* light DOM: it lives
+       in the host's shadow root, so only the host's stylesheet can
+       reach it. This file is the one every call site already includes,
+       which is what makes twelve menus grow thumb-sized rows from one
+       edit.
+
+       Measured on the device before the change: rows were 29px, against
+       the 44px floor plan 018 promises and the 48px this issue asks
+       for. --------------------------------------------------------- */
+    .context-menu-panel[data-sheet] {
+        border: none;
+        border-radius: 0;
+        box-shadow: none;
+        min-width: 0;
+        padding: 4px 0 8px;
+        background-color: transparent;
+    }
+
+    .context-menu-panel[data-sheet] wa-dropdown-item {
+        font-size: var(--yj-text-md, 0.9375rem);
+        min-height: 48px;
+        align-items: center;
+    }
+
+    .context-menu-panel[data-sheet] wa-dropdown-item::part(base) {
+        min-height: 48px;
+        align-items: center;
+    }
+
+    /* A submenu arrow means "a flyout opens to the right", which is not
+       what happens on a phone and is not a thing a thumb can aim at.
+       The row still works — it is the tap handler that opens the
+       playlist picker — so what goes is the arrow, not the item. */
+    .context-menu-panel[data-sheet] .submenu-arrow {
+        display: none;
+    }
+
     .context-menu-panel {
         background-color: var(
             --yj-bg-elevated,

frontend/test/components/menu-surface.test.ts

@@ -0,0 +1,222 @@
+/**
+ * Where a context menu is drawn (#60).
+ *
+ * **This file asserts the mechanism, not the symptom, and that is the
+ * whole point of it.** The defect is that on the reference device's
+ * Chrome 113 a `wa-popup` has no Popover API to promote it to the top
+ * layer, so it falls back to `position: fixed` and is then *clipped* by
+ * `.main-panel`'s `contain: paint`. No tier here can reproduce that:
+ * this runner's Chromium and CI's WebKit both have the Popover API, so
+ * the popup is top-layered and looks perfectly correct. A test that
+ * asserted "the menu is not clipped" would pass on the broken build.
+ *
+ * What is checkable everywhere is *which surface exists*. A native
+ * `<dialog>` uses the real top layer, which Chrome 37 has, so "it is a
+ * dialog at phone width" is the property that makes the device
+ * behaviour follow. The measurements that needed the hardware are on
+ * the PR and in `.planning/NOTES.md`.
+ */
+import { describe, expect, it, beforeEach, afterEach } from 'vitest';
+
+import '@components/menu-surface/menu-surface';
+import { MENU_DISMISS_EVENT } from '@components/menu-surface/menu-surface';
+import { fixture } from '@test/support/render';
+
+/** Every source file, as text. */
+const SOURCES = import.meta.glob<string>('../../src/**/*.ts', {
+  eager: true,
+  query: '?raw',
+  import: 'default',
+});
+
+/**
+ * The two files allowed to render a raw `wa-popup`.
+ *
+ * `menu-surface` *is* the popup, in its desktop presentation.
+ * `job-indicator` is the documented exception and the contrast that
+ * proved the diagnosis: it lives in `.top-bar`, no ancestor of which
+ * has containment, so even the fixed fallback lands correctly on the
+ * device -- measured on #62, unclipped at every width.
+ *
+ * `now-playing`'s cover preview is the third, and it is a different
+ * reason: it is not a menu. It opens on `mouseenter` over the album
+ * art, so a touch device never sees it at all, and a bottom sheet for
+ * a hover preview would be absurd. It is also in the bottom bar rather
+ * than the main panel, so nothing clips it either.
+ *
+ * **Both were found by this sweep, not by the conversion**, which is
+ * the argument for having it: twelve call sites were converted by hand
+ * and two more existed.
+ */
+const MAY_USE_POPUP = [
+  'menu-surface/menu-surface.ts',
+  'jobs/job-indicator.ts',
+  'now-playing/now-playing.ts',
+];
+
+/**
+ * Answer `matchMedia` for the phone query, on `transport-context`'s
+ * pattern: what is under test is the component's reaction to the
+ * answer, not whether this runner's window can get below 600px.
+ */
+const realMatchMedia = window.matchMedia;
+
+function pretendPhone(phone: boolean): void {
+  window.matchMedia = ((query: string) => ({
+    matches: phone && query.includes('599'),
+    media: query,
+    addEventListener: () => {},
+    removeEventListener: () => {},
+  })) as unknown as typeof window.matchMedia;
+}
+
+/** A surface with the panel a real call site slots into it. */
+async function surfaceWithPanel(): Promise<HTMLElement> {
+  const el = await fixture('menu-surface');
+
+  el.innerHTML =
+    '<div class="context-menu-panel" role="menu" aria-label="Track actions">' +
+    '<wa-dropdown-item>Play</wa-dropdown-item>' +
+    '</div>';
+
+  const surface = el as unknown as HTMLElement & {
+    active: boolean;
+    updateComplete: Promise<unknown>;
+  };
+
+  surface.active = true;
+  await surface.updateComplete;
+
+  return el;
+}
+
+/**
+ * The sweep, in the spirit of `icon-language.test.ts` and
+ * `TestNoDirectRuntimeEmits`: the rule is about *every* call site, and
+ * checking one checks nothing.
+ *
+ * Twelve menus were converted by hand. A thirteenth written as a bare
+ * `<wa-popup>` would work perfectly in every tier here and be clipped
+ * on the device, which is exactly the failure this whole change is
+ * about and exactly the one no runtime assertion can see.
+ */
+describe('every menu goes through the one surface', () => {
+  it('reads the sources at all', () => {
+    // A sweep over an empty glob passes, so this is asserted first.
+    expect(Object.keys(SOURCES).length).toBeGreaterThan(100);
+  });
+
+  it('leaves no raw wa-popup outside the two files allowed one', () => {
+    const offenders = Object.entries(SOURCES)
+      .filter(([path]) => !MAY_USE_POPUP.some((ok) => path.endsWith(ok)))
+      .filter(([, src]) => src.includes('<wa-popup'))
+      .map(([path]) => path.replace(/^.*\/src\//, 'src/'));
+
+    expect(
+      offenders,
+      'these render a popup directly; use <menu-surface> so the phone gets a sheet',
+    ).toEqual([]);
+  });
+});
+
+describe('menu-surface', () => {
+  afterEach(() => {
+    window.matchMedia = realMatchMedia;
+  });
+
+  describe('above the phone breakpoint', () => {
+    beforeEach(() => pretendPhone(false));
+
+    it('draws a popup, which is what the desktop has always had', async () => {
+      const el = await surfaceWithPanel();
+
+      expect(el.shadowRoot?.querySelector('wa-popup')).not.toBeNull();
+      expect(el.shadowRoot?.querySelector('wa-dialog')).toBeNull();
+    });
+
+    it('does not mark the panel as a sheet', async () => {
+      const el = await surfaceWithPanel();
+
+      expect(
+        el.querySelector('.context-menu-panel')?.hasAttribute('data-sheet'),
+      ).toBe(false);
+    });
+  });
+
+  describe('at phone width', () => {
+    beforeEach(() => pretendPhone(true));
+
+    /**
+     * The load-bearing one. `wa-dialog` renders a *native* `<dialog>`,
+     * and it is the native element -- not the wrapper -- that gets the
+     * top layer and therefore escapes the paint containment that clips
+     * the popup on the device.
+     */
+    it('draws a native dialog, which is what escapes the clip', async () => {
+      const el = await surfaceWithPanel();
+
+      const wrapper = el.shadowRoot?.querySelector('wa-dialog');
+
+      expect(wrapper, 'no wa-dialog at phone width').not.toBeNull();
+      expect(el.shadowRoot?.querySelector('wa-popup')).toBeNull();
+
+      await (wrapper as HTMLElement & { updateComplete: Promise<unknown> })
+        .updateComplete;
+
+      expect(
+        wrapper?.shadowRoot?.querySelector('dialog'),
+        'the wrapper is not backed by a native dialog',
+      ).not.toBeNull();
+    });
+
+    /**
+     * The rows are sized by `contextMenuStyles`, which lives in the
+     * *host's* shadow root — so the only thing this component can do is
+     * say which mode it is in. That attribute is the contract between
+     * the two, and it is what twelve call sites get their thumb-sized
+     * rows from.
+     */
+    it('marks the panel as a sheet, which is what sizes the rows', async () => {
+      const el = await surfaceWithPanel();
+
+      expect(
+        el.querySelector('.context-menu-panel')?.hasAttribute('data-sheet'),
+      ).toBe(true);
+    });
+
+    /**
+     * `wa-dialog` closes itself on Escape. Without this the controller
+     * would still believe the menu was open, and the *next* long-press
+     * would do nothing — which is the failure mode that looks like the
+     * gesture breaking rather than the dialog.
+     */
+    it('reports a dismissal it did not initiate', async () => {
+      const el = await surfaceWithPanel();
+
+      let dismissed = 0;
+
+      document.addEventListener(MENU_DISMISS_EVENT, () => {
+        dismissed += 1;
+      });
+
+      el.shadowRoot
+        ?.querySelector('wa-dialog')
+        ?.dispatchEvent(new CustomEvent('wa-hide', { bubbles: false }));
+
+      expect(dismissed, 'no menu-dismiss reached the document').toBe(1);
+    });
+
+    /**
+     * A dialog with no accessible name is what `utils/name-dialog.ts`
+     * exists for; here the name is already written on the panel, so no
+     * call site says it twice.
+     */
+    it('names the sheet after the menu it contains', async () => {
+      const el = await surfaceWithPanel();
+
+      const wrapper = el.shadowRoot?.querySelector('wa-dialog');
+
+      expect(wrapper?.getAttribute('label')).toBe('Track actions');
+    });
+  });
+});

frontend/test/components/progress-line.test.ts

@@ -0,0 +1,258 @@
+/**
+ * The phone's progress line (#58).
+ *
+ * **What this tier can and cannot see.** It can see the whole of what
+ * the issue asks for that is not a pixel: that the line exists only on
+ * a phone and only with a track, that it renders the position the
+ * backend reported rather than a count of its own, and that it is
+ * neither announced nor touchable. It cannot see where it sits — that
+ * is the shell's grid, and it is asserted in
+ * `e2e/specs/phone-progress-line.spec.ts` where there is a real bar
+ * with a real tab bar under it.
+ */
+import { describe, expect, it, beforeEach, afterEach, vi } from 'vitest';
+
+import '@components/audio-player/progress-line/progress-line';
+import { Events } from '../../src/events';
+import { emit, flush } from '@test/support/harness';
+import { fixture, shadow } from '@test/support/render';
+
+const TRACK = {
+    fileName: 'song.mp3',
+    filePath: '/music/song.mp3',
+    trackLength: 90,
+    seekPosition: 0,
+    state: 'playing',
+    title: 'Song',
+    artist: 'Artist',
+    album: 'Album',
+    coverArt: '',
+    coverArtSmall: '',
+    coverArtMedium: '',
+    coverArtLarge: '',
+    trackChangeId: 1,
+    artistMbid: '',
+    releaseGroupMbid: '',
+    recordingMbid: '',
+};
+
+/**
+ * Answer `matchMedia` for the phone query, since the runner's own
+ * window is whatever size the browser provider gives it. Stubbed rather
+ * than resized for `transport-context.test.ts`'s reason: what is under
+ * test is the component's reaction to the answer.
+ */
+const realMatchMedia = window.matchMedia;
+
+function pretendPhone(phone: boolean): void {
+    window.matchMedia = ((query: string) => ({
+        matches: phone && query.includes('599'),
+        media: query,
+        addEventListener: () => {},
+        removeEventListener: () => {},
+    })) as unknown as typeof window.matchMedia;
+}
+
+/** The horizontal scale of the fill, or null if there is no line. */
+function scale(el: Element): number | null {
+    const fill = shadow<HTMLElement>(el, '.fill');
+
+    if (!fill) return null;
+
+    const match = /scaleX\(([^)]+)\)/.exec(fill.style.transform);
+
+    return match ? Number(match[1]) : null;
+}
+
+describe('<player-progress-line>', () => {
+    beforeEach(() => {
+        emit(Events.TrackChanged, null);
+        emit(Events.PlaybackStateChanged, { state: 'stopped' });
+    });
+
+    afterEach(() => {
+        window.matchMedia = realMatchMedia;
+        vi.useRealTimers();
+    });
+
+    it('draws nothing above the phone breakpoint', async () => {
+        pretendPhone(false);
+
+        const el = await fixture('player-progress-line');
+
+        emit(Events.TrackChanged, { ...TRACK, trackChangeId: 2 });
+        emit(Events.PlaybackPositionChanged, {
+            positionSeconds: 45,
+            trackLength: 90,
+            trackChangeId: 2,
+            seq: 1,
+            playing: true,
+        });
+        await flush();
+        await el.updateComplete;
+
+        // The desktop bar carries a real seek bar, and there is no tab
+        // bar for this to sit on the border of.
+        expect(el.shadowRoot!.querySelector('.track')).toBeNull();
+    });
+
+    it('draws nothing until there is a track', async () => {
+        pretendPhone(true);
+
+        const el = await fixture('player-progress-line');
+
+        expect(el.shadowRoot!.querySelector('.track')).toBeNull();
+    });
+
+    it('renders the fraction the backend reported', async () => {
+        pretendPhone(true);
+
+        const el = await fixture('player-progress-line');
+
+        emit(Events.TrackChanged, { ...TRACK, trackChangeId: 3 });
+        emit(Events.PlaybackPositionChanged, {
+            positionSeconds: 45,
+            trackLength: 90,
+            trackChangeId: 3,
+            seq: 1,
+            playing: true,
+        });
+        await flush();
+        await el.updateComplete;
+
+        expect(scale(el)).toBeCloseTo(0.5, 3);
+    });
+
+    it('resumes mid-track at the position the track arrived with', async () => {
+        pretendPhone(true);
+
+        const el = await fixture('player-progress-line');
+
+        emit(Events.TrackChanged, {
+            ...TRACK,
+            seekPosition: 30,
+            trackChangeId: 4,
+        });
+        await flush();
+        await el.updateComplete;
+
+        expect(scale(el)).toBeCloseTo(1 / 3, 3);
+    });
+
+    it('interpolates between reports, and every report resets it', async () => {
+        pretendPhone(true);
+        vi.useFakeTimers();
+
+        const el = await fixture('player-progress-line');
+
+        emit(Events.TrackChanged, { ...TRACK, trackChangeId: 5 });
+        emit(Events.PlaybackStateChanged, { state: 'playing' });
+        await vi.advanceTimersByTimeAsync(3000);
+        await el.updateComplete;
+
+        expect(scale(el)).toBeCloseTo(3 / 90, 3);
+
+        // The user seeks; the backend lands somewhere else and says so.
+        // The local count is discarded, never added to -- the seek
+        // bar's rule, and the reason it has it.
+        emit(Events.PlaybackPositionChanged, {
+            positionSeconds: 40,
+            trackLength: 90,
+            trackChangeId: 5,
+            seq: 2,
+            playing: true,
+        });
+        await vi.advanceTimersByTimeAsync(1000);
+        await el.updateComplete;
+
+        expect(scale(el)).toBeCloseTo(41 / 90, 3);
+    });
+
+    /*
+     * The reason this component asks `matchMedia` instead of letting a
+     * stylesheet hide it: a media query cannot stop a 1 Hz interval
+     * running for the life of every desktop session. That claim is
+     * load-bearing in CLAUDE.md, so it is asserted rather than
+     * described — the timer count, because a desktop render is empty
+     * either way and so cannot tell the two apart.
+     */
+    it('runs no interpolation timer above the breakpoint', async () => {
+        pretendPhone(false);
+        vi.useFakeTimers();
+
+        const el = await fixture('player-progress-line');
+
+        emit(Events.TrackChanged, { ...TRACK, trackChangeId: 9 });
+        emit(Events.PlaybackStateChanged, { state: 'playing' });
+        emit(Events.PlaybackPositionChanged, {
+            positionSeconds: 3,
+            trackLength: 90,
+            trackChangeId: 9,
+            seq: 9,
+            playing: true,
+        });
+        await vi.advanceTimersByTimeAsync(5000);
+        await el.updateComplete;
+
+        expect(scale(el)).toBeNull();
+        expect(vi.getTimerCount()).toBe(0);
+    });
+
+    it('ignores a report about a track that is no longer loaded', async () => {
+        pretendPhone(true);
+
+        const el = await fixture('player-progress-line');
+
+        emit(Events.TrackChanged, { ...TRACK, trackChangeId: 6 });
+        emit(Events.PlaybackPositionChanged, {
+            positionSeconds: 60,
+            trackLength: 90,
+            trackChangeId: 5,
+            seq: 3,
+            playing: true,
+        });
+        await flush();
+        await el.updateComplete;
+
+        // The store is a singleton, so a line mounting late must not
+        // adopt a report about the previous track.
+        expect(scale(el)).toBe(0);
+    });
+
+    it('counts nothing while the player is paused', async () => {
+        pretendPhone(true);
+        vi.useFakeTimers();
+
+        const el = await fixture('player-progress-line');
+
+        emit(Events.TrackChanged, { ...TRACK, trackChangeId: 7 });
+        emit(Events.PlaybackPositionChanged, {
+            positionSeconds: 10,
+            trackLength: 90,
+            trackChangeId: 7,
+            seq: 1,
+            playing: false,
+        });
+        emit(Events.PlaybackStateChanged, { state: 'paused' });
+        await vi.advanceTimersByTimeAsync(5000);
+        await el.updateComplete;
+
+        expect(scale(el)).toBeCloseTo(10 / 90, 3);
+    });
+
+    it('is decorative and cannot be touched', async () => {
+        pretendPhone(true);
+
+        const el = await fixture('player-progress-line');
+
+        emit(Events.TrackChanged, { ...TRACK, trackChangeId: 8 });
+        await flush();
+        await el.updateComplete;
+
+        // The seek bar on Now Playing is what announces the position;
+        // this says the same thing with no name and no way to act on
+        // it, and it sits exactly where a thumb aiming at a tab lands.
+        expect(el.getAttribute('aria-hidden')).toBe('true');
+        expect(getComputedStyle(el).pointerEvents).toBe('none');
+    });
+});

frontend/test/components/transport-context.test.ts

@@ -0,0 +1,181 @@
+/**
+ * The transport in its two contexts (#59, #56).
+ *
+ * `player-controls` is one component in two places, and what each place
+ * wants differs *at the same viewport*: on a phone the bottom bar wants
+ * three controls sized for a thumb, and `now-playing-view` wants five,
+ * larger still. So the host states the context and the viewport states
+ * the size band, and this file pins the half a media query cannot
+ * express.
+ *
+ * **What this tier can and cannot see.** It can see which buttons
+ * exist, because that is `matchMedia` and a render — and existence is
+ * the whole of #59. It cannot see the *sizes*: those come from the
+ * context's custom properties, and a component-tier render has no shell
+ * around it, so the measurements live in `e2e/specs/phone-transport.spec.ts`
+ * where there is a real bar in a real viewport. Asserting a pixel here
+ * would be asserting the fallbacks, which is `ui-visual`'s documented
+ * blind spot one tier over.
+ */
+import { describe, expect, it, beforeEach, afterEach } from 'vitest';
+
+import '@components/audio-player/controls/player-controls';
+import { Events } from '../../src/events';
+import { emit, flush, calls } from '@test/support/harness';
+import { fixture, shadowAll, click } from '@test/support/render';
+
+/** Reset the backend-owned state the component reads from. */
+function idle(): void {
+  emit(Events.TrackChanged, null);
+  emit(Events.PlaybackStateChanged, { state: 'stopped' });
+  emit(Events.QueueModeChanged, { shuffleMode: false, repeatMode: 'off' });
+}
+
+const names = (el: Element): Array<string | null> =>
+  shadowAll(el, 'button').map((b) => b.getAttribute('aria-label'));
+
+/**
+ * Answer `matchMedia` for the phone query, since the test runner's own
+ * window is whatever size the browser provider gives it.
+ *
+ * It is stubbed rather than resized because what is under test is the
+ * component's *reaction* to the answer, and a resize would additionally
+ * be asserting that this runner's viewport can get below 600px.
+ */
+const realMatchMedia = window.matchMedia;
+
+function pretendPhone(phone: boolean): void {
+  window.matchMedia = ((query: string) => ({
+    matches: phone && query.includes('599'),
+    media: query,
+    addEventListener: () => {},
+    removeEventListener: () => {},
+  })) as unknown as typeof window.matchMedia;
+}
+
+afterEach(() => {
+  window.matchMedia = realMatchMedia;
+});
+
+describe('<player-controls> in the bar', () => {
+  beforeEach(() => {
+    idle();
+  });
+
+  it('keeps all five on a desktop, in the order it always had', async () => {
+    pretendPhone(false);
+
+    const el = await fixture('player-controls');
+
+    // Unchanged from before #59, deliberately: this is the desktop bar
+    // and nothing about it was reported.
+    expect(names(el)).toEqual([
+      'Shuffle',
+      'Previous track',
+      'Play',
+      'Next track',
+      'Repeat: off',
+    ]);
+  });
+
+  it('draws three on a phone, and does not merely hide the other two', async () => {
+    pretendPhone(true);
+
+    const el = await fixture('player-controls');
+
+    expect(names(el)).toEqual(['Previous track', 'Play', 'Next track']);
+
+    // The distinction this asserts is the point. A `display: none`
+    // control is still in the shadow root, still something a positional
+    // query finds, and still a thing the component claims to have --
+    // so "the phone has three controls" would have been true of the
+    // pixels and false of the element.
+    expect(shadowAll(el, 'button')).toHaveLength(3);
+  });
+
+  it('follows the viewport when it changes, not just at construction', async () => {
+    pretendPhone(false);
+
+    const el = await fixture('player-controls');
+
+    expect(names(el)).toHaveLength(5);
+
+    // A desktop window dragged narrow is the phone layout, per plan
+    // 018's decision 4 -- so this is a real transition and not a
+    // hypothetical.
+    (el as unknown as { phone: boolean }).phone = true;
+    await flush();
+    await el.updateComplete;
+
+    expect(names(el)).toEqual(['Previous track', 'Play', 'Next track']);
+  });
+});
+
+describe('<player-controls> full-screen', () => {
+  beforeEach(() => {
+    idle();
+  });
+
+  it('keeps all five on a phone, where the bar keeps three', async () => {
+    pretendPhone(true);
+
+    const el = await fixture('player-controls');
+
+    el.setAttribute('context', 'full');
+    await el.updateComplete;
+
+    // The same viewport, the other answer: this is why the context is a
+    // property and cannot be a media query.
+    expect(names(el)).toHaveLength(5);
+  });
+
+  it('puts the secondary pair after the primary three, in the DOM', async () => {
+    pretendPhone(true);
+
+    const el = await fixture('player-controls');
+
+    el.setAttribute('context', 'full');
+    await el.updateComplete;
+
+    // Order, not just membership: the secondary controls are drawn on a
+    // second row, and this is asserted in the DOM because visual order
+    // and focus order have to agree. A CSS `order` property would move
+    // them on screen and leave Tab walking the old sequence.
+    expect(names(el)).toEqual([
+      'Previous track',
+      'Play',
+      'Next track',
+      'Shuffle',
+      'Repeat: off',
+    ]);
+  });
+
+  it('still routes every button to the backend', async () => {
+    pretendPhone(true);
+
+    const el = await fixture('player-controls');
+
+    el.setAttribute('context', 'full');
+    await el.updateComplete;
+
+    // Two arrangements, one set of handlers. The regression this
+    // guards is the reason a second *component* was refused: a second
+    // template renders buttons wired to nothing, which looks perfect
+    // in a screenshot and does nothing at all.
+    for (const name of [
+      'Previous track',
+      'Next track',
+      'Shuffle',
+      'Repeat: off',
+    ]) {
+      await click(el, `button[aria-label="${name}"]`);
+    }
+
+    expect(calls().map((c) => c.path)).toEqual([
+      'queue.Queue.Previous',
+      'queue.Queue.Next',
+      'queue.Queue.ToggleShuffle',
+      'queue.Queue.CycleRepeat',
+    ]);
+  });
+});

frontend/test/components/volume-ownership.test.ts

@@ -0,0 +1,93 @@
+/**
+ * Who owns the volume, and what the control does when it is not us
+ * (#64).
+ *
+ * **This is the tier that can exercise the Android branch**, and it is
+ * the reason the predicate is a backend answer rather than a build tag
+ * the frontend cannot see: `SystemOwnsVolume` is a stub here, so the
+ * "no volume" rendering is checked on an ordinary Linux CI runner with
+ * no device anywhere. What no tier here can check is the *constant*
+ * behind it, which `TestPlatformVolumeOwnershipIsDeclaredOncePerPlatform`
+ * sweeps the Go source for instead.
+ *
+ * It is a file of its own because `volumeStyleStore` asks once and
+ * latches — the answer is a property of the binary and cannot change
+ * while the app runs, so there is deliberately no event that refreshes
+ * it. Vitest gives each file its own module registry, which is what
+ * lets the stub be in place before the singleton is first touched.
+ * The *available* case is the rest of `transport.test.ts`, which mounts
+ * the same element under the default stub.
+ */
+import { describe, expect, it, beforeEach } from 'vitest';
+
+import '@components/audio-player/volume-control/volume-control';
+import '@components/now-playing-view/now-playing-view';
+import { Events } from '../../src/events';
+import { emit, resetHarness, stub } from '@test/support/harness';
+import { fixture, shadow, shadowAll } from '@test/support/render';
+import type { TrackInfo } from '@store/player-store';
+
+const TRACK: TrackInfo = {
+  fileName: 'tideline.mp3',
+  filePath: '/music/tideline.mp3',
+  trackLength: 245,
+  seekPosition: 0,
+  state: 'playing',
+  title: 'Tideline',
+  artist: 'Sea Change',
+  album: 'Ebb',
+  coverArt: '',
+  coverArtSmall: '',
+  coverArtMedium: '',
+  coverArtLarge: '',
+  trackChangeId: 1,
+  artistMbid: '',
+  releaseGroupMbid: '',
+  recordingMbid: '',
+};
+
+describe('a platform whose volume we do not own', () => {
+  beforeEach(async () => {
+    resetHarness();
+    stub('player.Player.SystemOwnsVolume', true);
+    stub('config.Config.GetPopupVolume', false);
+
+    // The store latches on the first mount; do it here so every test
+    // below sees a settled answer rather than the first frame.
+    const warm = await fixture('volume-control');
+
+    await warm.updateComplete;
+  });
+
+  it('renders no control at all, and no empty shadow root to find', async () => {
+    const el = await fixture('volume-control');
+
+    await el.updateComplete;
+
+    // Both halves matter. An empty shadow root is what stops a
+    // positional or by-role query finding a button that cannot act;
+    // `hidden` is what stops the host taking a flex item's worth of
+    // space in the transport it sits in.
+    expect(shadowAll(el, 'button')).toHaveLength(0);
+    expect(shadowAll(el, 'wa-slider')).toHaveLength(0);
+    expect(el.hidden, 'the host is not hidden').toBe(true);
+  });
+
+  it('leaves the rest of the phone transport alone', async () => {
+    emit(Events.TrackChanged, TRACK);
+
+    const view = await fixture('now-playing-view');
+
+    await view.updateComplete;
+
+    // Seeking and the transport buttons are not volume, and #64 is
+    // allowed to remove one control, not to thin the screen out.
+    expect(shadow(view, 'seek-bar')).not.toBeNull();
+    expect(shadow(view, 'player-controls')).not.toBeNull();
+
+    const volume = shadow(view, 'volume-control') as HTMLElement | null;
+
+    expect(volume, 'the element is still mounted').not.toBeNull();
+    expect(volume!.hidden, 'a mounted volume-control is not hidden').toBe(true);
+  });
+});

frontend/test/utils/css-nesting.test.ts

@@ -0,0 +1,79 @@
+/**
+ * The nesting check's own semantics.
+ *
+ * `make css-check` runs it over a tree that currently has no violation,
+ * so the check passing says nothing about whether it can still find
+ * one. What it has to get right is two distinctions, and both are the
+ * kind a regex over the file gets wrong: a rule directly inside an
+ * at-rule is not nested, and a brace inside a string or a comment is
+ * not a block.
+ *
+ * The rule it enforces is the device's: Chrome 113 predates relaxed CSS
+ * nesting, so a nested selector starting with an element name is
+ * dropped in silence. See `scripts/css-nesting.mjs`.
+ */
+import { describe, expect, it } from 'vitest';
+
+import { findBareNestedRules } from '../../scripts/css-nesting.mjs';
+
+describe('the nested-rule check', () => {
+  it('flags a nested rule that starts with an element name', () => {
+    const found = findBareNestedRules(
+      '.bottom-bar {\n    color: red;\n\n    audio-player { margin: 0 }\n}',
+    );
+
+    expect(found).toEqual([{ line: 4, selector: 'audio-player' }]);
+  });
+
+  it('accepts the same rule written with a leading &', () => {
+    expect(
+      findBareNestedRules('.bottom-bar {\n    & audio-player { margin: 0 }\n}'),
+    ).toEqual([]);
+  });
+
+  it('accepts a nested selector that starts with any other symbol', () => {
+    expect(
+      findBareNestedRules('.bar {\n    #track-info { color: red }\n}'),
+    ).toEqual([]);
+    expect(findBareNestedRules('.bar {\n    :host { color: red }\n}')).toEqual(
+      [],
+    );
+  });
+
+  it('leaves a top-level rule alone, element name or not', () => {
+    expect(findBareNestedRules('p {\n    margin: 0;\n}')).toEqual([]);
+  });
+
+  /**
+   * The majority of what a naive sweep would report: a media query at
+   * the top level holds ordinary rules, not nested ones.
+   */
+  it('leaves a rule directly inside an at-rule alone', () => {
+    expect(
+      findBareNestedRules(
+        '@media (max-width: 599px) {\n    bottom-nav { display: flex }\n}',
+      ),
+    ).toEqual([]);
+  });
+
+  /**
+   * And the other half of that: what decides it is whether a style rule
+   * is anywhere above, not what the immediate parent is.
+   */
+  it('flags one inside an at-rule that is itself inside a rule', () => {
+    expect(
+      findBareNestedRules(
+        '.bar {\n    @media (min-width: 900px) {\n        audio-player { margin: 0 }\n    }\n}',
+      ),
+    ).toEqual([{ line: 3, selector: 'audio-player' }]);
+  });
+
+  it('reads through a brace in a string or a comment', () => {
+    expect(
+      findBareNestedRules('.a {\n    background: url("x{y}");\n}'),
+    ).toEqual([]);
+    expect(
+      findBareNestedRules('.a {\n    /* audio-player { x: y } */\n}'),
+    ).toEqual([]);
+  });
+});

lefthook.yml

@@ -58,6 +58,15 @@ pre-commit:
       root: "frontend/"
       run: node scripts/check-css-literals.mjs
 
+    # A nested rule whose selector starts with an element name is
+    # silently dropped by the device's Chrome 113, and by nothing else --
+    # so every tier here renders it correctly and only a screenshot of
+    # the phone disagrees. Instant.
+    css-nesting:
+      glob: "frontend/**/*.{ts,css}"
+      root: "frontend/"
+      run: node scripts/check-css-nesting.mjs
+
 # Deliberately sequential, unlike pre-commit.  `go test -race`
 # saturates every core for the better part of a minute and the UI tier
 # is a real browser with wall-clock timeouts, so run together the