fix(a11y): stop the now-playing marquee under reduced motion

a11y.15 / WCAG 2.2.2: the bottom bar's title and artist scrolled for as
long as a track played, re-armed in a loop by transitionend, with no
pause mechanism and no reduced-motion guard.

Reproduced under an emulated prefers-reduced-motion before the fix: the
title still carried will-scroll with a 15s transition and the transform
was still moving. That read landed in the snap-back half of the cycle,
which is why a CSS-only 'transition: none' is the wrong fix -- it leaves
the text translated off its own box and transitionend never fires to
bring it back. The scroll is not armed at all instead, which is a
decision shouldScroll() already owned, and it covers hover as well as
always: reduce is a request about motion, not about autoplay.

Two things came out of looking at the result rather than asserting on
it. The non-scrolling fallback was hard-clipping, not ellipsising, in
every mode including the default -- text-overflow was on the outer span
while the overflowing box is the inline-block child. And moving it to
the child then broke overflow *detection*, because the parent stops
overflowing once the child hides its own; both measurements come from
the child now. The second was caught by the new test's positive case,
which is why it has one.

.planning/plans/active/008-the-last-audit.md

@@ -0,0 +1,299 @@
+# 008 — The last audit, and the one binding that outlived six phases
+
+**Status:** active
+**Branch:** main
+**Created:** 2026-08-12
+**Follows:** 007-ui-reconciliation
+**Source:** `.planning/audits/2026-08-11-ui/a11y.md` (34 findings), plus
+one item inherited through all six phases of 007.
+
+## Problem
+
+Three of the four audits from 2026-08-11 are closed. `a11y.md` is not,
+and it is **the least verified material in the repo** — 007's own notes
+say so twice, and every pass that touched it found the audit wrong about
+something.
+
+Two things follow from that, and they are the shape of this plan.
+
+**The coverage map lies, and it lies in the direction of more work than
+exists.** 007's map assigns `a11y.7` (top-results cards are click-only
+divs) to Phase 6; the code has carried `role="button" tabindex="0"` and
+an Enter/Space handler since Phase 1. It is not alone. A grep pass over
+all 34 findings against the current tree closes at least five the map
+still shows open, and three of those (`17`, `19`, `27`) were closed by
+phases that were not about them.
+
+**And what survives is not evenly distributed.** Of the ~13 that look
+open, three are genuine loss of function and the rest are Minor or
+Polish. One of the three — `15` — is a hard WCAG conformance failure
+that has been sitting under a "Major" heading being read as a nice-to-
+have.
+
+Cutting across both: **two items in this audit were never measured at
+all.** Colour contrast is flagged borderline (`--yj-text-tertiary` on
+`--yj-bg-surface` ≈ 4.1:1 against 11 px text) with "that needs a real
+measurement" written next to it, and 007 parked it under "deliberately
+not planned — worth measuring before planning". The mouse-only resize
+handles (`28`) were dropped as "cosmetic preference, no function lost",
+which is a judgement made by reading. Both are claims with no number
+behind them, which by this repo's own standard is not a finding yet.
+
+Separately, and not from any audit: **`tracklist.delete`**. Advertised
+in Settings as configurable, bound to nothing, and carried through six
+phases because it needs an operation that does not exist.
+
+## The triage, as of 2026-08-12
+
+Grep-level against `1e4a4e6`. **Every row is a hypothesis** — this is
+where the audit's claims are, not where the code is. Nothing here is
+fixed until it has been reproduced in the running app.
+
+**Closed** (verified present in code): `1`, `2`, `3`, `4`, `5`, `6`,
+`7`, `8`, `12`, `13`, `16`, `17`, `19`, `27`, `33`.
+
+**Closed by argument rather than by code**, to confirm by reading:
+`20` (the type-scale/`_itemSize` coupling is now documented in
+`tokens.css.ts`, which is what the finding asked for), `31` (one of
+`cover-grid`'s two `<img>`s has an `alt`; the finding named one).
+
+**Open:**
+
+| # | Level | What the grep says |
+|---|---|---|
+| `15` | Major | `now-playing` is not among the four files carrying `prefers-reduced-motion`. WCAG 2.2.2: moving content over 5 s with no pause mechanism. |
+| `14` | Major | `combobox.ts` has no `aria-controls`, no `aria-activedescendant`, no option ids. |
+| `11` | Major | No `altKey` handler in `queue-panel`. The *other* half of this finding — "no keyboard path to add a track to the queue or a playlist" — was closed by Phase 5's `MenuKeyboard`. |
+| `21` | Minor | `body { height: 100vh; overflow: hidden }` unchanged. WCAG 1.4.10. |
+| `22` | Minor | `queue-panel` gained `aria-current`; `track-list` did not, and neither has a non-colour marker. |
+| `24` | Minor | No `title` on the truncating element in `track-info`, `playlist-view`, `queue-panel` or `track-list`. |
+| `25` | Minor | `<wa-progress-bar value=…>` with no label, verbatim as filed. |
+| `28` | dropped | Four `@mousedown` `<div>`s with no `role="separator"`. Never measured. |
+| `29` | Polish | `<h3 class="subtitle">` for type size. |
+| `30` | Polish | No skip link anywhere. |
+| `32` | Polish | `title="Remove from queue"`, not identifying the track. |
+| `34` | Polish | The 10 px sort arrow, unchanged. |
+| — | — | Colour contrast, never measured. |
+
+## Ordering principle
+
+By **what is lost**, then by containment.
+
+Phase 1 first because it is the only phase where something a user needs
+is unavailable: a marquee they cannot stop, a combobox that announces
+nothing while they arrow through it, and a queue whose order cannot be
+changed without a mouse.
+
+Phase 2 second because both of its items are *questions*, and the
+answers change what Phase 3 contains. If the contrast measurement comes
+back below 4.5:1 it is a Phase 1 item wearing a Polish hat; if the
+resize handles turn out to lose function rather than preference, `28`
+stops being dropped.
+
+Phase 3 is the tail, batched, because each item is a line and the cost
+is in the verification rather than the change.
+
+Phase 4 is `tracklist.delete`, last, because it is the only work in this
+plan that can destroy a user's data and it should not share a pass with
+anything.
+
+---
+
+## Phase 1 — The three that lose function
+
+### `15` — the marquee cannot be stopped
+
+`now-playing`'s title and artist scroll continuously while a track plays
+when `scrollMode === 'always'` (persisted in localStorage), re-armed in
+a loop by `onScrollCycleEnd`.
+
+**Ships:** a `prefers-reduced-motion: reduce` guard that treats `always`
+as `never` and disables the transition. The setting stays; the query
+overrides it, which is the right precedence — a stated OS-level
+accessibility preference outranks an app default the user may never have
+touched.
+
+**Reproduce first:** the guard is two lines and will look like it
+worked whether or not it did. Check under an emulated
+`prefers-reduced-motion` in the running app, and check that the *hover*
+scroll (`scrollMode === 'hover'`, the default) is also covered — the
+finding names `always` and the mechanism is shared.
+
+**Watch for:** `now-playing`'s geometry work in `updated()` keys on the
+two scroll flags, because `.will-scroll .scroll-content` carries
+`padding-right: 2em` and changing the class changes the distance the
+marquee travels. A guard that suppresses the animation without telling
+the geometry key will leave a stale measurement behind.
+
+### `14` — the combobox announces nothing
+
+`role="combobox" aria-expanded aria-autocomplete="list"` on the input
+and `role="listbox"`/`role="option"` below it, with no `id` on the
+listbox, no `aria-controls`, no `aria-activedescendant`, and no `id` on
+the options. `aria-selected` is used to mean "highlighted".
+
+**Ships:** ids on the listbox and each option, `aria-controls`,
+`aria-activedescendant` tracking the highlight, and `aria-selected`
+meaning *chosen*.
+
+**Reproduce first:** the a11y snapshot could not see a dialog's name and
+may not see this either — 007 lost twenty minutes to exactly that.
+CDP's `Accessibility.getFullAXTree` reports the computed value and where
+it came from; use it, not the snapshot.
+
+### `11` — queue order cannot be changed without a mouse
+
+Reordering is `draggable="true"` with the drop index computed from
+cursor Y. There is no keyboard equivalent and no `aria-` substitute.
+
+**Ships:** Alt+ArrowUp / Alt+ArrowDown moves the focused queue item, on
+the roving tab stop `utils/roving-rows.ts` already gives that list, with
+a live region announcing the new position.
+
+**Watch for:** Alt+Arrow is unmodified-adjacent but not unmodified, so
+`focusedControlOwnsKey` does not apply — this is a panel binding in
+`backend/shortcuts/config.go`, registered the way `tracklist.*` is, not
+a document listener. And the queue panel renders no list at all when
+closed, so anything asserting on it has to open it first.
+
+**This is the risky one.** It is a new interaction model, it touches the
+backend shortcut table, and the drag path it parallels computes its drop
+index geometrically. It lands last in the phase, alone.
+
+### Verification
+
+`make ui-test` per rule, and then **run the existing tests** — that is
+what has caught every bad version of a new rule in 007, including twice
+in the last pass. `make ui-visual` for `15` (it changes what renders).
+An e2e case for `11`, because the queue panel's animated width means a
+click issued while it moves lands on whatever slid under the pointer.
+A manual pass per landing, with a screenshot read.
+
+---
+
+## Phase 2 — The two that were never measured
+
+Neither is a fix. Both are a number, and the number decides whether
+there is work.
+
+**Colour contrast.** Measured against the rendered app, not against the
+token file: the tokens are what a component *may* use, and what matters
+is the pairs that actually appear. Sample the real computed colours at
+the real sizes, report the ratios, and only then decide. The audit's own
+number (≈ 4.1:1) is a hand calculation from two hex values and has the
+status of a hypothesis.
+
+**`a11y.28`, the resize handles.** Four of them: the sidebar, the queue
+panel, the now-playing column, and the track-list column resizers.
+"Cosmetic preference, no function lost" is the claim to test. The
+track-list one is the suspicious member — a column narrowed to its floor
+clips its label (007 phase 5 found "Durat…" at 800 px), so widening a
+column may be the only way to read a value, which is function.
+
+**Record both outcomes either way.** A measurement that closes a finding
+is worth as much as one that opens it, and this plan's predecessor got
+about a third of its value from findings that evaporated.
+
+---
+
+## Phase 3 — The tail
+
+`21`, `22`, `24`, `25`, `29`, `30`, `32`, `34`, plus whatever Phase 2
+promotes or closes. One landing, batched, each item confirmed against
+the code before it is touched.
+
+Two of them are not one-liners and should be treated as such:
+
+- **`21`** (the shell is `100vh; overflow: hidden`) is a layout change
+  to the app frame, and 007 phase 5 already measured the frame's real
+  minimum at 800×600. Reflow at high zoom is the same question one
+  variable over. It may want its own landing.
+- **`22`** asks for a non-colour marker on the playing row, which is a
+  visual change to the densest list in the app and moves a baseline.
+
+---
+
+## Phase 4 — `tracklist.delete`, and the operation behind it
+
+### The decision
+
+*(Decided 2026-08-12, before any code.)*
+
+**"Remove from library" removes the database row and excludes the path
+from future scans. It does not touch the file.**
+
+The comment at `backend/shortcuts/config.go:36` states the fork exactly:
+the row (which the next scan puts back unless the path is also excluded)
+or the file (a delete-your-music button one keystroke from a focused
+row). Three shapes were considered:
+
+- **A — row + path exclusion.** Reversible, needs an exclusions table,
+  so a schema file *and* a migration.
+- **B — delete the file**, to the platform trash. Real user intent for
+  an app with duplicate detection, genuinely destructive, and a new
+  cross-platform dependency.
+- **C — ship the operation as a menu command only**, leave `Delete`
+  unbound.
+
+**A, delivered as C**, and then the keystroke. Without the exclusion,
+A is a button that undoes itself on the next scan, which is worse than
+no button — so the exclusion is not an enhancement, it is what makes the
+operation mean anything. `Delete` is bound only to *open the
+confirmation*, never to perform the removal: that makes the keystroke a
+request rather than an action, which is the only version defensible one
+key from a focused row.
+
+**B is not foreclosed and is not in this plan.** It deserves its own
+argument.
+
+### What ships
+
+- An exclusions table, following the two-file schema discipline
+  (`sql/schemas/` for the target shape, `sql/migrations/` for the
+  existing install, column order matching, no index on a migrated
+  column in the schema file).
+- `RemoveFromLibrary(filePaths)` — rows deleted, paths excluded, one
+  event carrying enough for the stores to patch rather than invalidate.
+  It is a *write*, so it goes through `ExecContext`, not the read pool.
+- A context-menu command behind `confirmAction()`, with impact copy
+  naming the count and saying explicitly that files on disk are not
+  touched.
+- `tracklist.delete` re-advertised, bound to opening that dialog.
+- The scanner honouring the exclusion list, which is the half that makes
+  the rest true.
+
+### Verification
+
+A Go test that a removed path survives a rescan; an e2e case that the
+row is gone, the dialog said so, and the file still exists. Both halves
+matter — the second is the promise the copy makes.
+
+---
+
+## Deliberately not in this plan
+
+- **Splitting `explore-view.ts`** (1 900 lines). The shelves are in it
+  because a separate component would need its own art fetching and
+  therefore its own cache, cap and probe, and `perf.M7` exists because
+  that view never unmounts. The reasoning holds; the size is the price.
+- **A `make perf` before/after for Phase 6's shelves.** Both seeds get
+  their catalog from the artifact rather than from the seed tarball, so
+  a before and an after are not the same corpus unless the e2e staging
+  fixture is extended to bulk scale. Recorded as unmeasured in 007
+  rather than implied to be free.
+- **The unowned badge's `+` glyph.** It becomes correct the day the
+  badge becomes a button. Changing it now touches four components'
+  visual baselines for a call better made then.
+- **The albums shelf leading with one act.** Needs dump-side data to
+  express "these eight artists are one group and its solo members".
+  A plan, not a fix.
+- **WebKit2GTK-specific behaviour** (page zoom in the Wails shell, how
+  Orca traverses the virtualizer's windowed DOM). Only answerable on the
+  real shell, and CI is the only place WebKit runs.
+
+## First step
+
+Phase 1, and within it `15` — reproduced under an emulated
+`prefers-reduced-motion` **before** the guard is written, because a
+two-line CSS change looks identical whether or not it worked, and this
+plan's predecessor met that failure in seven different costumes.

.planning/plans/completed/007-ui-reconciliation.md

@@ -1,18 +1,52 @@
 # 007 — UI reconciliation: lifecycle, truth, voice, scale, shape, and one thing that was never built
 
-**Status:** active — Phases 1, 2 and 3 shipped, each with one or two
-deliberate deferrals (see the "what actually shipped" sections below).
-**Phase 4 is complete** after six passes; the sixth landed `m5`, `m4`
-and `m2`, which was the whole remaining tail.
-Phase 3 was the plan's own clean cut: stopping here leaves the data-loss
-bug, the lying player and the silent failures all fixed.
-**Branch:** —
+**Status:** implemented — all six phases shipped.
+**Branch:** main
 **Created:** 2026-08-11
 **Follows:** 006-orientation-fixes
+**Followed by:** 008-the-last-audit
 **Source:** `.planning/audits/2026-08-11-ui/` — `hands-on.md` (24
 findings reproduced in the running app), `a11y.md` (34), `perf.md`
 (30), `errors.md` (30).
 
+## Recap
+
+~118 findings, which were five problems each spread by copying. All six
+phases shipped, over eleven passes, and three of the four source audits
+are closed: `hands-on.md`, `perf.md` and `errors.md` have nothing open.
+`a11y.md` does, and is plan 008.
+
+- **Phase 1 — a cached view now has a lifecycle.** `viewActivated` /
+  `viewDeactivated`, the ambient shortcut scope the mechanism was built
+  for and had never had a caller, and keyboard reach for the sidebar,
+  the track rows, the card grids and the closed queue panel.
+- **Phase 2 — the player reports its own position.** 1 Hz from the
+  backend, `PlaybackFailed` from both failure paths, auto-advance that
+  skips, and a bar that no longer counts itself 30 s adrift.
+- **Phase 3 — one notification surface, four levels**, replacing 84
+  `catch` blocks that ended at `console.error` and two private toasts.
+- **Phase 4 — works offline and at 50 000 tracks**, over six passes:
+  bundled icons, route splitting, the `TrackPlayCountChanged` split,
+  bounded caches, `utils/track-index.ts` (3–6 s → 68 ms), and the
+  virtualizer repaint rule.
+- **Phase 5 — one app, not eleven pages**, over four passes: one
+  `<page-header>`, a measured window minimum, every dialog a named
+  `wa-dialog`, one menu keyboard model, the `?` overlay, and an album
+  page with a primary action that means the same thing in three
+  different ownership states.
+- **Phase 6 — Explore opens with shelves**, plus the two inherited
+  one-liners: the badge that was an inert button, and the card grids
+  that moved to the end rather than by a row.
+
+**What it is worth reading for**: the seven "where the plan was wrong"
+lists below, seventy-nine entries across the passes. About a third are
+the audit being wrong rather than the code, and they are the reason
+plan 008 treats every remaining `a11y.md` claim as a hypothesis.
+
+**Inherited, unfinished, and carried into 008**: `tracklist.delete`,
+which survived all six phases because it needs a "remove from library"
+operation that does not exist and a decision about what it removes.
+
 ## Problem
 
 A full pass over the UI — the app driven by hand headless, plus three

CLAUDE.md

@@ -147,7 +147,7 @@ tree; `make bindings` regenerates it for real.
 `config.toml` and DB rows — the same discipline `sql/schemas/` gets,
 for the same reason.
 
-See `.planning/plans/active/005-agent-development-harness.md`.
+See `.planning/plans/completed/005-agent-development-harness.md`.
 
 ## Architecture
 

e2e/specs/reduced-motion.spec.ts

@@ -0,0 +1,104 @@
+import { test, expect, callBinding, waitForEvent } from '../support/fixtures.js';
+import type { Page } from '@playwright/test';
+
+/**
+ * `a11y.15` — WCAG 2.2.2.  The bottom bar's title and artist scroll
+ * continuously while a track plays, re-armed in a loop by
+ * `transitionend`, with no pause mechanism and no reduced-motion guard.
+ *
+ * The component test for this fakes `window.matchMedia`, which is a
+ * stub of the thing being tested.  This spec sets the real context
+ * option, so the real media query answers.
+ *
+ * Both directions are here on purpose.  A guard that suppressed
+ * everything would pass the reduce case for free, and so would a bar
+ * whose text simply does not overflow at this viewport — which is what
+ * the component test failed on first.
+ */
+
+/** The fixture track whose title is long enough to overflow the bar. */
+const LONG_TITLE = 'An Exhaustively Overlong Track Title';
+
+/**
+ * Read the title line's classes from inside `now-playing`'s shadow root.
+ *
+ * `will-scroll` is the class that carries both the transition and the
+ * `padding-right` the scroll distance is measured against, so its
+ * absence is the whole fix: suppressing only the animation leaves the
+ * text translated off its own box with nothing to bring it back.
+ */
+async function titleClasses(app: Page): Promise<string> {
+  return app.evaluate(() => {
+    const np = document.querySelector('now-playing');
+    const title = np?.shadowRoot?.querySelector('.track-title');
+
+    return title?.className ?? '';
+  });
+}
+
+async function playTheLongOne(app: Page): Promise<void> {
+  await app.getByTestId('nav-tracks').click();
+
+  // The scroll mode defaults to `hover`, and a fresh context has no
+  // persisted setting — so without this the positive case never
+  // scrolls and reports the same thing a broken build would. Set it
+  // rather than hovering, because `always` is also the mode the
+  // finding is about: continuous motion for as long as the track
+  // plays, with nothing the user has to do to provoke it.
+  await app.evaluate(() => {
+    localStorage.setItem('yj-now-playing-scroll-mode', 'always');
+    window.dispatchEvent(new CustomEvent('yj-scroll-mode-changed'));
+  });
+
+  const paths: string[] = await app.evaluate(async (needle) => {
+    const tracks = await window.__yjEvents.call(
+      'library.Library.GetAllTracks',
+      [],
+      10_000,
+    );
+
+    return (tracks as { TrackName: string; FilePath: string }[])
+      .filter((t) => t.TrackName.startsWith(needle))
+      .map((t) => t.FilePath);
+  }, LONG_TITLE);
+
+  expect(paths.length).toBeGreaterThan(0);
+
+  await callBinding(app, 'queue.Queue.SetQueue', [paths, 0, false]);
+  await waitForEvent(app, 'TrackChanged');
+
+  // The scroll cycle is armed 1500 ms after the geometry is measured,
+  // and the geometry is measured after the render that puts the title
+  // on screen. Reading before that reports "not scrolling" on a build
+  // that scrolls — the same shape as every probe read too early in
+  // plan 007.
+  await expect
+    .poll(() => titleClasses(app), { timeout: 10_000 })
+    .toContain('track-title');
+}
+
+test.describe('the marquee under prefers-reduced-motion', () => {
+  test.use({ contextOptions: { reducedMotion: 'reduce' } });
+
+  test('does not scroll the now-playing text at all', async ({ app }) => {
+    await playTheLongOne(app);
+
+    // Give the cycle longer than the 1500 ms arming delay to prove it
+    // never arms, rather than catching it before it would have.
+    await app.waitForTimeout(2500);
+
+    expect(await titleClasses(app)).not.toContain('will-scroll');
+  });
+});
+
+test.describe('the marquee without a motion preference', () => {
+  test.use({ contextOptions: { reducedMotion: 'no-preference' } });
+
+  test('still scrolls an overflowing title', async ({ app }) => {
+    await playTheLongOne(app);
+
+    await expect
+      .poll(() => titleClasses(app), { timeout: 10_000 })
+      .toContain('will-scroll');
+  });
+});

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

@@ -57,6 +57,21 @@ export class NowPlaying extends LitElement {
     @state()
     private artistHovered = false;
 
+    /**
+     * `prefers-reduced-motion: reduce`, live (a11y.15).
+     *
+     * It is a `@state` and not a CSS query because suppressing the
+     * *transition* is not enough: the cycle is a transition out, a
+     * `transitionend`, and a transition back, so removing the animation
+     * leaves the text translated off its own box and `onScrollCycleEnd`
+     * never fires to bring it back.  The scroll has to not be armed at
+     * all, which is a decision `shouldScroll()` already owns.
+     */
+    @state()
+    private reduceMotion = false;
+
+    private reduceMotionQuery?: MediaQueryList;
+
     /** Whether each field is actively mid-scroll (class toggle). */
     @state()
     private titleScrolling = false;
@@ -200,9 +215,19 @@ export class NowPlaying extends LitElement {
       color: var(--yj-text-tertiary, #666);
     }
 
-    /* Static ellipsis when not scrolling */
-    .track-title:not(.will-scroll),
-    .track-artist:not(.will-scroll) {
+    /* Static ellipsis when not scrolling.
+
+       It has to be on .scroll-content, not on the outer span: the child
+       is an inline-block, so it is the box that overflows, and
+       text-overflow on an ancestor does not ellipsise an overflowing
+       inline-block descendant — it clips it. The outer rule was there
+       from the start and never produced an ellipsis in any mode; the
+       default mode is hover, so what every user saw when not hovering
+       was a title cut mid-glyph. Only visible in a screenshot. */
+    .track-title:not(.will-scroll) .scroll-content,
+    .track-artist:not(.will-scroll) .scroll-content {
+      display: block;
+      overflow: hidden;
       text-overflow: ellipsis;
     }
 
@@ -248,6 +273,12 @@ export class NowPlaying extends LitElement {
         this.updateWidth(DEFAULT_WIDTH);
         window.addEventListener(SCROLL_CHANGE_EVENT, this.handleScrollModeEvent);
 
+        // Looked up here rather than at module load so a test can install
+        // its own matchMedia before the element is created.
+        this.reduceMotionQuery = window.matchMedia?.('(prefers-reduced-motion: reduce)');
+        this.reduceMotion = this.reduceMotionQuery?.matches ?? false;
+        this.reduceMotionQuery?.addEventListener('change', this.handleReduceMotionChange);
+
         this.resizeObserver = new ResizeObserver(() => {
             this.geometryDirty = true;
             this.requestUpdate();
@@ -259,6 +290,7 @@ export class NowPlaying extends LitElement {
         // A drag interrupted by the bar going away still has to clean up.
         this.attachDragListeners(false);
         window.removeEventListener(SCROLL_CHANGE_EVENT, this.handleScrollModeEvent);
+        this.reduceMotionQuery?.removeEventListener('change', this.handleReduceMotionChange);
         this.resizeObserver?.disconnect();
         this.stopScrollCycle('title');
         this.stopScrollCycle('artist');
@@ -371,6 +403,7 @@ export class NowPlaying extends LitElement {
             <span
               class="track-title ${titleScrolling ? 'will-scroll' : ''} ${this.titleScrolling ? 'scrolling' : ''}"
               data-testid="now-playing-title"
+              title=${track.title}
               @mouseenter=${this.handleTitleMouseEnter}
               @mouseleave=${this.handleTitleMouseLeave}
               @transitionend=${() => this.onScrollCycleEnd('title')}
@@ -380,6 +413,7 @@ export class NowPlaying extends LitElement {
             <span
               class="track-artist ${artistScrolling ? 'will-scroll' : ''} ${this.artistScrolling ? 'scrolling' : ''}"
               data-testid="now-playing-artist"
+              title=${track.artist || 'Unknown Artist'}
               @mouseenter=${this.handleArtistMouseEnter}
               @mouseleave=${this.handleArtistMouseLeave}
               @transitionend=${() => this.onScrollCycleEnd('artist')}
@@ -429,9 +463,21 @@ export class NowPlaying extends LitElement {
         this.loadScrollMode();
     };
 
+    private handleReduceMotionChange = (e: MediaQueryListEvent): void => {
+        this.reduceMotion = e.matches;
+    };
+
     private shouldScroll(field: 'title' | 'artist'): boolean {
         const overflows = field === 'title' ? this.titleOverflows : this.artistOverflows;
 
+        // A stated OS-level preference outranks an app default the user
+        // may never have touched, so this comes before the mode — and it
+        // covers `hover` as well as `always`.  Hover-scrolling is
+        // user-initiated and so arguably passes WCAG 2.2.2 on its own,
+        // but `reduce` is a request about motion, not about autoplay.
+        // The text falls back to the ellipsis every other mode uses.
+        if (this.reduceMotion) return false;
+
         if (!overflows || this.scrollMode === 'never') return false;
         if (this.scrollMode === 'always') return true;
 
@@ -477,9 +523,18 @@ export class NowPlaying extends LitElement {
             const content = el.querySelector<HTMLElement>('.scroll-content');
             const width = el.clientWidth;
 
+            // Both numbers come from the *child*, which is the box that
+            // holds the text. Asking the outer span whether it overflows
+            // only works while the child is an overflowing inline-block:
+            // once the non-scrolling state gives the child its own
+            // `overflow: hidden` (for the ellipsis), the parent stops
+            // overflowing and nothing ever arms the scroll again.
+            // `scrollWidth` reports the content size either way.
+            const full = content?.scrollWidth ?? 0;
+
             return {
-                overflows: el.scrollWidth > width,
-                distance: content ? content.scrollWidth - width : 0,
+                overflows: full > width,
+                distance: content ? full - width : 0,
             };
         };
 

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

@@ -232,6 +232,61 @@ describe('<now-playing>', () => {
     expect(queries()).toBeGreaterThan(0);
   });
 
+  // a11y.15 (WCAG 2.2.2). Reproduced in the running app first: under an
+  // emulated `prefers-reduced-motion: reduce` the title still carried
+  // `will-scroll` with a 15s transition and the transform was still
+  // moving — the read landed in the *snap-back* half of the cycle,
+  // which is why suppressing the transition alone is not the fix.
+  //
+  // Both directions are asserted because a guard that suppresses
+  // everything passes the negative case for free, and a component that
+  // never scrolls at this width would too.
+  const LONG =
+    'An Exhaustively Overlong Track Title That Exists Solely To Find Out ' +
+    'Whether The Bottom Bar Truncates Or Overflows';
+
+  async function mountScrolling(reduce: boolean) {
+    const real = window.matchMedia.bind(window);
+
+    window.matchMedia = ((q: string) =>
+      q.includes('prefers-reduced-motion')
+        ? {
+            matches: reduce,
+            media: q,
+            addEventListener() {},
+            removeEventListener() {},
+          }
+        : real(q)) as typeof window.matchMedia;
+
+    try {
+      localStorage.setItem('yj-now-playing-scroll-mode', 'always');
+
+      const el = await fixture('now-playing');
+
+      // The real host is sized by `--now-playing-width` on `.bottom-bar`,
+      // which the fixture does not have — so it is document-width here
+      // and nothing overflows, which made the positive case fail first.
+      el.style.width = '320px';
+
+      emit(Events.TrackChanged, { ...TRACK, title: LONG, trackChangeId: 10 });
+      await flush();
+      await settle(el);
+
+      return shadow(el, '.track-title')?.className ?? '';
+    } finally {
+      window.matchMedia = real;
+      localStorage.removeItem('yj-now-playing-scroll-mode');
+    }
+  }
+
+  it('scrolls an overflowing title when motion is not a problem', async () => {
+    expect(await mountScrolling(false)).toContain('will-scroll');
+  });
+
+  it('does not scroll at all under prefers-reduced-motion', async () => {
+    expect(await mountScrolling(true)).not.toContain('will-scroll');
+  });
+
   it('looks the way it did last time', async () => {
     const el = await fixture('now-playing');