feat(android): the tap highlight goes, a press state replaces it

The phone drew a grey box over the bounding rect of whatever was
tapped, which is the web view saying what it is. It is gone in one
declaration: `-webkit-tap-highlight-color` is inherited and an
inherited property crosses a shadow boundary, so `html` in index.css
reaches every shadow root in the app. Measured three roots deep,
rgba(0, 0, 0, 0.18) before and rgba(0, 0, 0, 0) after.

Removing it removes the only touch feedback several surfaces had, so
the press state is part of the same change rather than a later polish
item — with the highlight gone a held row measured the *hover* tint,
which on a phone is synthesised by the hold itself and outlives it.
The four lists' rows, the tab bar, the sidebar's destinations and the
shared context-menu item take --yj-press-overlay on :active; the cards
already had scale(0.97). The press selector carries a state class
because a row is .track-row.selected.active, so a bare :active shows
nothing on the row a phone is most likely to press. And those
surfaces' hover tints move behind (hover: hover) and (pointer: fine),
which is #68's gate applied to a tint rather than a revealed control.

user-select, the other half of the Findings, was already done: the
first rule in index.css covers the shadow roots for the same reason.
touch-action: manipulation is declined — the 300ms delay it is offered
for is already absent on a width=device-width viewport, and what it
would really change is the gesture stack tuned by measurement on a
device this session cannot measure.

Closes #54

frontend/index.css

@@ -7,6 +7,26 @@
 
 html {
     height: 100%;
+
+    /* #54.  The web view's own tap highlight -- the grey box a phone
+       draws over the bounding rect of whatever was tapped -- gone in
+       one declaration, because `-webkit-tap-highlight-color` is an
+       *inherited* property and an inherited property crosses a shadow
+       boundary.  So this reaches every one of the app's shadow roots
+       without a rule in any of them; before it, exactly one component
+       (`library-status-indicator`) set it and the box appeared
+       everywhere else.
+
+       What it costs is the only touch feedback several surfaces had,
+       which is why the rows, the tab bar and the shared menu items
+       grew a `:active` state in the same change: removing the wrong
+       feedback and leaving none is not an improvement.  The cards
+       already had one (`transform: scale(0.97)`).
+
+       `user-select` is the same argument one rule up and was already
+       done: the `*` rule at the top of this file is inherited into the
+       shadow roots too. */
+    -webkit-tap-highlight-color: transparent;
 }
 
 body {

frontend/src/components/bottom-nav/bottom-nav.ts

@@ -89,6 +89,17 @@ export class BottomNav extends LitElement {
             color: var(--yj-accent, #ffd43b);
         }
 
+        /* The press state (#54). This bar is the phone's primary
+           navigation and had no feedback of its own at all -- what a
+           tap produced was the web view's tap highlight, a grey box
+           over the whole 48px cell, which index.css has now taken
+           away. The .active rule above is which tab you are *on*; this
+           is the tab being pressed, so they are a colour and a
+           background rather than two colours. */
+        button:active {
+            background-color: var(--yj-press-overlay, rgba(255, 255, 255, 0.12));
+        }
+
         button:focus-visible {
             outline: 2px solid var(--yj-accent, #ffd43b);
             outline-offset: -2px;

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

@@ -1357,8 +1357,14 @@ export class PlaylistDetails
             user-select: none;
         }
 
-        .track-item:hover {
-            background-color: var(--yj-hover-overlay, rgba(255, 255, 255, 0.05));
+        /* A hover tint is for a device that hovers (#54). A hold
+           synthesises a hover in the WebView, so ungated this arrives
+           because a finger touched the row and stays after it has
+           gone; the press state below is what a tap gets instead. */
+        @media (hover: hover) and (pointer: fine) {
+            .track-item:hover {
+                background-color: var(--yj-hover-overlay, rgba(255, 255, 255, 0.05));
+            }
         }
 
         .track-item.selected {
@@ -1378,11 +1384,13 @@ export class PlaylistDetails
             cursor: pointer;
         }
 
-        .track-item.phantom:hover {
-            background-color: var(
-                --yj-hover-overlay,
-                rgba(255, 255, 255, 0.05)
-            );
+        @media (hover: hover) and (pointer: fine) {
+            .track-item.phantom:hover {
+                background-color: var(
+                    --yj-hover-overlay,
+                    rgba(255, 255, 255, 0.05)
+                );
+            }
         }
 
         .track-item.phantom.selected {
@@ -1392,6 +1400,19 @@ export class PlaylistDetails
             );
         }
 
+        /* The press state (#54): the feedback a tap has now that the
+           web view's own highlight box is gone (index.css). Last, and
+           carrying a class, because a selected or playing row is two
+           classes deep and a bare :active would lose to it. */
+        .track-item.selected:active,
+        .track-item.active:active,
+        .track-item:active {
+            background-color: var(
+                --yj-press-overlay,
+                rgba(255, 255, 255, 0.12)
+            );
+        }
+
         .phantom-row {
             grid-column: 1 / -1;
             display: flex;

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

@@ -581,8 +581,14 @@ export class QueuePanel
             contain: strict;
         }
 
-        .track-item:hover {
-            background-color: var(--yj-hover-overlay, rgba(255, 255, 255, 0.05));
+        /* A hover tint is for a device that hovers (#54). A hold
+           synthesises a hover in the WebView, so ungated this arrives
+           because a finger touched the row and stays after it has
+           gone; the press state below is what a tap gets instead. */
+        @media (hover: hover) and (pointer: fine) {
+            .track-item:hover {
+                background-color: var(--yj-hover-overlay, rgba(255, 255, 255, 0.05));
+            }
         }
 
         .track-item.selected {
@@ -597,6 +603,19 @@ export class QueuePanel
             background-color: var(--yj-selection-bg, rgba(100, 160, 255, 0.15));
         }
 
+        /* The press state (#54): the feedback a tap has now that the
+           web view's own highlight box is gone (index.css). Last, and
+           carrying a class, because a selected or playing row is two
+           classes deep and a bare :active would lose to it. */
+        .track-item.selected:active,
+        .track-item.active:active,
+        .track-item:active {
+            background-color: var(
+                --yj-press-overlay,
+                rgba(255, 255, 255, 0.12)
+            );
+        }
+
         .track-position {
             font-size: var(--yj-text-sm);
             color: var(--yj-text-tertiary, #888);

frontend/src/components/sidebar/app-sidebar.ts

@@ -95,8 +95,15 @@ export class AppSidebar extends LitElement {
             text-align: center;
         }
 
-        li button:hover {
-            background-color: var(--yj-bg-elevated, #343a40);
+        /* A hover tint is for a device that hovers (#54), and this
+           component is on a phone too: below 600px it is what
+           bottom-nav's "More" sheet mounts, where a hold
+           synthesises a hover and leaves a destination looking picked
+           after the finger has gone. */
+        @media (hover: hover) and (pointer: fine) {
+            li button:hover {
+                background-color: var(--yj-bg-elevated, #343a40);
+            }
         }
 
         li button:focus-visible {
@@ -108,6 +115,14 @@ export class AppSidebar extends LitElement {
             background-color: var(--yj-bg-overlay, #495057);
         }
 
+        /* The press state (#54), after the .active rule and at the same
+           specificity, so pressing the destination you are already on
+           still says something. It is what a tap gets now that
+           index.css has taken the web view's own highlight box away. */
+        li button:active {
+            background-color: var(--yj-press-overlay, rgba(255, 255, 255, 0.12));
+        }
+
         li button p {
             margin: 0;
             white-space: nowrap;

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

@@ -516,8 +516,14 @@ export class SmartPlaylistDetails
             user-select: none;
         }
 
-        .track-item:hover {
-            background-color: var(--yj-hover-overlay, rgba(255, 255, 255, 0.05));
+        /* A hover tint is for a device that hovers (#54). A hold
+           synthesises a hover in the WebView, so ungated this arrives
+           because a finger touched the row and stays after it has
+           gone; the press state below is what a tap gets instead. */
+        @media (hover: hover) and (pointer: fine) {
+            .track-item:hover {
+                background-color: var(--yj-hover-overlay, rgba(255, 255, 255, 0.05));
+            }
         }
 
         .track-item.selected {
@@ -533,6 +539,19 @@ export class SmartPlaylistDetails
             background-color: var(--yj-selection-bg, rgba(100, 160, 255, 0.15));
         }
 
+        /* The press state (#54): the feedback a tap has now that the
+           web view's own highlight box is gone (index.css). Last, and
+           carrying a class, because a selected or playing row is two
+           classes deep and a bare :active would lose to it. */
+        .track-item.selected:active,
+        .track-item.active:active,
+        .track-item:active {
+            background-color: var(
+                --yj-press-overlay,
+                rgba(255, 255, 255, 0.12)
+            );
+        }
+
         /* Phantom rows span the full grid */
         .track-item.phantom {
             display: grid;

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

@@ -1201,8 +1201,16 @@ export class TrackList
       padding-left: 6px;
     }
 
-    .track-row:hover {
-      background-color: var(--yj-hover-overlay, rgba(255, 255, 255, 0.05));
+    /* A hover tint is for a device that hovers (#54): a hold
+       synthesises a hover in the WebView, so ungated this is a
+       highlight that arrives because a finger touched the row and
+       then stays there after it has gone -- which reads as a
+       selection the user did not make. Same gate, and the same
+       mechanism, as #68's revealed controls. */
+    @media (hover: hover) and (pointer: fine) {
+      .track-row:hover {
+        background-color: var(--yj-hover-overlay, rgba(255, 255, 255, 0.05));
+      }
     }
 
     .track-row.selected {
@@ -1239,6 +1247,23 @@ export class TrackList
       background-color: var(--yj-selection-bg, rgba(100, 160, 255, 0.15));
     }
 
+    /* The press state (#54), and the only feedback a tap has now that
+       the web view's tap highlight is gone (index.css).
+
+       **Last, and as specific as the state rules above**: a row that
+       is selected and playing is .track-row.selected.active, so a
+       bare .track-row:active is one class short of it and a press
+       on the row a phone is most likely to press -- the one it just
+       selected -- would show nothing. Instant rather than
+       transitioned, because the only measured statement here about
+       transitions on a list is that two card grids removed theirs
+       for software-rendering repaint cost. */
+    .track-row.selected:active,
+    .track-row.active:active,
+    .track-row:active {
+      background-color: var(--yj-press-overlay, rgba(255, 255, 255, 0.12));
+    }
+
 
     .cell {
       overflow: hidden;

frontend/src/store/theme-store.ts

@@ -46,6 +46,17 @@ export interface ShadePalette {
     border: string;
     borderSubtle: string;
     hoverOverlay: string;
+    /**
+     * The tint a surface takes while it is being pressed (#54).
+     *
+     * Separate from `hoverOverlay` because the two answer different
+     * questions and only one of them a phone can ask: a hover is a
+     * pointer resting somewhere, a press is a finger on the thing it
+     * is about to activate. It is deliberately the stronger of the
+     * two — a press that reads the same as a hover says nothing on a
+     * device where the hover is synthesised by the press itself.
+     */
+    pressOverlay: string;
     selectionBg: string;
 }
 
@@ -95,6 +106,7 @@ export const SHADE_PALETTES: Record<BackgroundShade, ShadePalette> = {
         border: '#333333',
         borderSubtle: '#222222',
         hoverOverlay: 'rgba(255, 255, 255, 0.05)',
+        pressOverlay: 'rgba(255, 255, 255, 0.12)',
         selectionBg: 'rgba(100, 160, 255, 0.15)',
     },
     dark: {
@@ -114,6 +126,7 @@ export const SHADE_PALETTES: Record<BackgroundShade, ShadePalette> = {
         border: '#444444',
         borderSubtle: '#333333',
         hoverOverlay: 'rgba(255, 255, 255, 0.05)',
+        pressOverlay: 'rgba(255, 255, 255, 0.12)',
         selectionBg: 'rgba(100, 160, 255, 0.15)',
     },
     light: {
@@ -133,6 +146,7 @@ export const SHADE_PALETTES: Record<BackgroundShade, ShadePalette> = {
         border: '#ced4da',
         borderSubtle: '#dee2e6',
         hoverOverlay: 'rgba(0, 0, 0, 0.05)',
+        pressOverlay: 'rgba(0, 0, 0, 0.12)',
         selectionBg: 'rgba(100, 160, 255, 0.15)',
     },
 };
@@ -285,6 +299,7 @@ function deriveThemeVariables(
 
         // Interactive overlays
         '--yj-hover-overlay': palette.hoverOverlay,
+        '--yj-press-overlay': palette.pressOverlay,
         '--yj-selection-bg': palette.selectionBg,
 
         // Semantic *fills* — the background of a solid button or badge.

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

@@ -710,10 +710,35 @@ export const contextMenuStyles = css`
         font-size: 13px;
     }
 
-    .context-menu-panel wa-dropdown-item:hover {
+    /* A hover tint is for a device that hovers (#54).
+
+       Below the query is a phone, where a hold *synthesises* a hover
+       in the WebView -- the same mechanism #68 gates the revealed
+       controls on -- so an ungated tint is a highlight that arrives
+       because a finger touched the row and then stays on it after the
+       finger has gone. Which is indistinguishable from the press
+       state below, and outlives it. */
+    @media (hover: hover) and (pointer: fine) {
+        .context-menu-panel wa-dropdown-item:hover {
+            background-color: var(
+                --yj-hover-overlay,
+                rgba(255, 255, 255, 0.1)
+            );
+        }
+    }
+
+    /* And a press state is for every device, because it is the one
+       piece of feedback a tap has now that the web view's own
+       highlight box is gone (index.css). Stronger than the hover tint
+       on purpose, and instant rather than transitioned: the only
+       measured statement this repo has about transitions on these
+       surfaces is the two card grids that removed theirs because
+       software rendering repaints per frame, and the phone is not
+       something this session can measure. */
+    .context-menu-panel wa-dropdown-item:active {
         background-color: var(
-            --yj-hover-overlay,
-            rgba(255, 255, 255, 0.1)
+            --yj-press-overlay,
+            rgba(255, 255, 255, 0.12)
         );
     }
 

frontend/test/components/press-feedback.test.ts

@@ -0,0 +1,191 @@
+/**
+ * What a tap looks like now that the web view's own highlight is gone
+ * (#54).
+ *
+ * `index.css` sets `-webkit-tap-highlight-color: transparent` on
+ * `html`, which — the property being inherited — reaches every shadow
+ * root in the app. That takes away the grey box a phone drew over the
+ * bounding rect of whatever was tapped, and with it the only touch
+ * feedback the rows, the tab bar, the sidebar's destinations and the
+ * shared menu items had. So the press states below are not decoration:
+ * without them this change trades wrong feedback for none.
+ *
+ * **Asserted against the parsed stylesheet**, on `hover-affordance`'s
+ * precedent and with the same limitation stated out loud: CDP's
+ * `Emulation.setEmulatedMedia` does not reach this tier's iframe, so
+ * there is no way here to render a component as a phone would, and
+ * `:active` cannot be forced from a test either. What the browser will
+ * answer is the shape it built from the `css` literal — which rule sits
+ * inside which media query, and what the press selector actually is.
+ *
+ * Two regressions are worth catching that way, and both are silent on a
+ * desktop:
+ *
+ * - someone hoisting a hover tint back out of its query as a tidy-up,
+ *   which on a phone is a highlight that arrives because a finger
+ *   touched the row and stays after it has gone;
+ * - someone simplifying the press selector to a bare `:active`, which
+ *   is one class short of `.selected` / `.active` and so does nothing
+ *   on the row a phone is most likely to press — the one it has just
+ *   selected.
+ *
+ * The pixels are the Android tier's, and the tap highlight itself is
+ * `e2e/specs/native-touch-feel.spec.ts`, since only the real app loads
+ * `index.css` at all.
+ */
+import { describe, expect, it } from 'vitest';
+
+import '@components/track-list/track-list';
+import '@components/queue-panel/queue-panel';
+import '@components/playlist-details/playlist-details';
+import '@components/smart-playlist-details/smart-playlist-details';
+import '@components/bottom-nav/bottom-nav';
+import '@components/sidebar/app-sidebar';
+import { fixture } from '@test/support/render';
+
+/** Every rule in the element's own adopted stylesheets, flattened. */
+function rulesOf(host: Element): { text: string; condition: string | null }[] {
+  const sheets = host.shadowRoot?.adoptedStyleSheets ?? [];
+  const out: { text: string; condition: string | null }[] = [];
+
+  for (const sheet of sheets) {
+    for (const rule of Array.from(sheet.cssRules)) {
+      if (rule instanceof CSSMediaRule) {
+        for (const inner of Array.from(rule.cssRules)) {
+          out.push({ text: inner.cssText, condition: rule.conditionText });
+        }
+
+        continue;
+      }
+
+      out.push({ text: rule.cssText, condition: null });
+    }
+  }
+
+  return out;
+}
+
+/** The four lists, their row selector, and the tag that draws them. */
+const LISTS: Array<[string, string]> = [
+  ['track-list', '.track-row'],
+  ['queue-panel', '.track-item'],
+  ['playlist-details', '.track-item'],
+  ['smart-playlist-details', '.track-item'],
+];
+
+describe('a row says it is being pressed', () => {
+  for (const [tag, row] of LISTS) {
+    it(`${tag} draws a press state that survives its state classes`, async () => {
+      const el = await fixture(tag, {});
+      const rules = rulesOf(el);
+
+      // Worth nothing if it read no rules at all — the first assertion
+      // icon-language.test.ts makes, for the same reason.
+      expect(rules.length).toBeGreaterThan(0);
+
+      const press = rules.filter(
+        (r) => r.text.includes(`${row}:active`) && r.text.includes('background-color'),
+      );
+
+      expect(press.length).toBeGreaterThan(0);
+
+      for (const rule of press) {
+        // A press is not a hover: it is the one thing a touch device
+        // can say, so it must not sit behind a pointer query.
+        expect(rule.condition).toBeNull();
+        expect(rule.text).toContain('--yj-press-overlay');
+      }
+
+      // The load-bearing half: the selector carries a state class, or
+      // it loses to `.selected` / `.selected.active` and the press is
+      // invisible on a selected or playing row.
+      expect(press.some((r) => r.text.includes(`${row}.selected:active`))).toBe(true);
+    });
+
+    it(`${tag} keeps its hover tint for devices that hover`, async () => {
+      const el = await fixture(tag, {});
+      const rules = rulesOf(el);
+
+      expect(rules.length).toBeGreaterThan(0);
+
+      const hover = rules.filter(
+        (r) =>
+          r.text.includes(`${row}:hover`) &&
+          r.text.includes('--yj-hover-overlay'),
+      );
+
+      expect(hover.length).toBeGreaterThan(0);
+
+      for (const rule of hover) {
+        expect(rule.condition).toMatch(/hover:\s*hover/);
+        expect(rule.condition).toMatch(/pointer:\s*fine/);
+      }
+    });
+  }
+});
+
+describe('the two navigations say they are being pressed', () => {
+  it('the phone tab bar, which had no state of its own at all', async () => {
+    const el = await fixture('bottom-nav', {});
+    const rules = rulesOf(el);
+
+    expect(rules.length).toBeGreaterThan(0);
+
+    const press = rules.filter((r) => r.text.startsWith('button:active'));
+
+    expect(press.length).toBe(1);
+    expect(press[0]!.condition).toBeNull();
+    expect(press[0]!.text).toContain('--yj-press-overlay');
+  });
+
+  it("the sidebar, which is also the phone's More sheet", async () => {
+    const el = await fixture('app-sidebar', {});
+    const rules = rulesOf(el);
+
+    expect(rules.length).toBeGreaterThan(0);
+
+    const press = rules.filter((r) => r.text.startsWith('li button:active'));
+
+    expect(press.length).toBe(1);
+    expect(press[0]!.condition).toBeNull();
+    expect(press[0]!.text).toContain('--yj-press-overlay');
+
+    // Its hover tint is a destination looking picked, if it is left to
+    // a synthesised hover inside the More sheet.
+    const hover = rules.filter((r) => r.text.startsWith('li button:hover'));
+
+    expect(hover.length).toBeGreaterThan(0);
+
+    for (const rule of hover) {
+      expect(rule.condition).toMatch(/hover:\s*hover/);
+    }
+  });
+});
+
+describe('the shared context menu', () => {
+  // One stylesheet, fourteen menus — the same reason the sheet's row
+  // height lives there rather than in each host.
+  it('presses its items, in the one place every menu includes', async () => {
+    const el = await fixture('queue-panel', {});
+    const rules = rulesOf(el);
+
+    const press = rules.filter((r) =>
+      r.text.startsWith('.context-menu-panel wa-dropdown-item:active'),
+    );
+
+    expect(press.length).toBe(1);
+    expect(press[0]!.condition).toBeNull();
+    expect(press[0]!.text).toContain('--yj-press-overlay');
+
+    const hover = rules.filter((r) =>
+      r.text.startsWith('.context-menu-panel wa-dropdown-item:hover'),
+    );
+
+    expect(hover.length).toBeGreaterThan(0);
+
+    for (const rule of hover) {
+      expect(rule.condition).toMatch(/hover:\s*hover/);
+      expect(rule.condition).toMatch(/pointer:\s*fine/);
+    }
+  });
+});