feat(playback): give the fullscreen side panel the settings panel's glass look

The fullscreen channel/episode panel was a full-height graphite strip while
the controls' settings panel is an inset, rounded glass card. The side panel
now wears the same surface: 16px inset (8px under 560px), 20px corners, the
controls' glass fill, hairline border, blur and shadow, the same open motion
and a 32px square close button. The edge hint uses the same glass, and the
episode list marks the playing row with the settings panel's selected cyan.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.changes/playback-side-panel-glass.md

@@ -0,0 +1,8 @@
+---
+type: feature
+area: playback
+---
+
+The fullscreen channel and episode list now floats over the video as a rounded
+glass card, matching the player's settings panel, and the playing episode is
+highlighted the same way as a selected setting.

docs/architecture/player-controls-contract.md

@@ -767,9 +767,16 @@ ends. The panel carries the `dark-theme` context class, so app and Material
 tokens inside it resolve to the dark palette whatever the app theme is — and
 because the app's global `.dark-theme { background: … !important }` rule
 (`apps/web/src/styles.scss`) claims the background of every element wearing
-that class, the panel's translucent gradient is declared on the compound
+that class, the panel's glass fill is declared on the compound
 `.fullscreen-channel-panel.dark-theme` selector with `!important`; without
-that the panel painted no background at all.
+that the panel painted no background at all. The panel wears the same surface
+as the controls' settings panel — a card inset 16px from the player's top,
+bottom and left edges (8px in a player narrower than 560px), 20px corners,
+the `--pc-glass-bg` fill, hairline `--pc-glass-border`, the same blur and
+shadow, and a 32px square close button — with the values written literally,
+because the panel is a sibling of the controls host, outside the scope that
+declares the `--pc-*` palette. Its episode list marks the playing row with the
+settings panel's selected-option cyan tint.
 Keyboard: `C` is ignored while any editable element has focus and while the
 player sits inside an `inert` region; the search field is an ordinary input,
 so the controls' Space/K/F/M shortcuts stay out of it. That is also why `C` is

libs/ui/playback/src/lib/fullscreen-channel-panel/fullscreen-channel-panel.component.scss

@@ -34,12 +34,12 @@
     left: 0;
     width: 22px;
     height: 96px;
-    border: 1px solid rgba(255, 255, 255, 0.16);
+    border: 1px solid rgba(255, 255, 255, 0.09);
     border-left: 0;
     border-radius: 0 12px 12px 0;
-    background: rgba(13, 15, 18, 0.72);
+    background: rgba(12, 16, 23, 0.72);
     box-shadow: 4px 0 18px rgba(0, 0, 0, 0.35);
-    backdrop-filter: blur(12px);
+    backdrop-filter: blur(18px) saturate(1.3);
     opacity: 0;
     transform: translate(-100%, -50%);
     pointer-events: none;
@@ -68,8 +68,8 @@
 }
 
 .fullscreen-channel-panel__edge-hint--armed {
-    border-color: var(--app-selection-color, #78adff);
-    background: rgba(13, 15, 18, 0.9);
+    border-color: rgba(255, 255, 255, 0.28);
+    background: rgba(12, 16, 23, 0.88);
 }
 
 .fullscreen-channel-panel__edge-hint--armed::after {
@@ -78,6 +78,12 @@
 
 // ─── Open state ──────────────────────────────────────────────────────────────
 
+// A floating glass card inset from the player edges — the same surface as the
+// player's settings panel (`player-settings-panel.component.scss`): 20px
+// corners, the controls' glass fill, hairline border and blur. The values are
+// literal because the panel sits beside the controls host, outside the scope
+// that declares the `--pc-*` palette.
+
 .fullscreen-channel-panel__scrim {
     position: absolute;
     inset: 0;
@@ -86,43 +92,46 @@
 
 .fullscreen-channel-panel {
     position: absolute;
-    top: 0;
-    bottom: 0;
-    left: 0;
+    top: 16px;
+    bottom: 16px;
+    left: 16px;
     z-index: 8;
     display: flex;
     flex-direction: column;
-    width: min(400px, calc(100% - 56px));
-    color: var(--app-heading-color, #d8dce8);
-    border-right: 1px solid rgba(255, 255, 255, 0.12);
-    box-shadow: 18px 0 48px rgba(0, 0, 0, 0.55);
-    backdrop-filter: blur(24px) saturate(140%);
-    transform: translateX(-100%);
+    box-sizing: border-box;
+    width: min(400px, calc(100% - 72px));
+    color: #e7ecf3;
+    border: 1px solid rgba(255, 255, 255, 0.09);
+    border-radius: 20px;
+    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.45);
+    backdrop-filter: blur(18px) saturate(1.3);
+    overflow: hidden;
+    opacity: 0;
+    // Past its own inset, so no rounded corner or shadow peeks in while shut.
+    transform: translateX(calc(-100% - 24px));
     visibility: hidden;
     transition:
-        transform 240ms cubic-bezier(0.2, 0.7, 0.2, 1),
-        visibility 0s linear 240ms;
+        transform 220ms cubic-bezier(0.2, 0.8, 0.2, 1),
+        opacity 220ms ease-out,
+        visibility 0s linear 220ms;
 }
 
-// Translucent graphite over the video, matching the controls' popovers. The
-// panel carries `dark-theme` for its tokens, and the app's global
+// The controls' glass fill over the video. The panel carries `dark-theme` for its tokens, and the app's global
 // `.dark-theme { background: var(--mat-sys-surface) !important }`
 // (apps/web/src/styles.scss) would replace this gradient with the flat
 // surface — or with no background at all where that token is not defined —
 // so the compound selector and `!important` are required to out-rank it.
 .fullscreen-channel-panel.dark-theme {
-    background: linear-gradient(
-        to right,
-        rgba(13, 15, 18, 0.94),
-        rgba(13, 15, 18, 0.88)
-    ) !important;
+    background: rgba(12, 16, 23, 0.72) !important;
 }
 
 .fullscreen-channel-panel--open {
+    opacity: 1;
     transform: translateX(0);
     visibility: visible;
     transition:
-        transform 240ms cubic-bezier(0.2, 0.7, 0.2, 1),
+        transform 220ms cubic-bezier(0.2, 0.8, 0.2, 1),
+        opacity 220ms ease-out,
         visibility 0s;
 }
 
@@ -131,9 +140,9 @@
 .fullscreen-channel-panel__header {
     display: flex;
     align-items: center;
-    gap: 4px;
+    gap: 8px;
     flex-shrink: 0;
-    padding: 10px 6px 10px 12px;
+    padding: 14px 12px 12px 16px;
 }
 
 // A host without a search field (`panelSearchEnabled` false) shows its title in
@@ -144,9 +153,9 @@
     margin: 0;
     padding: 0 4px;
     line-height: 36px;
-    font-size: 0.95rem;
+    font-size: 16px;
     font-weight: 600;
-    color: #ffffff;
+    color: #e7ecf3;
     overflow: hidden;
     text-overflow: ellipsis;
     white-space: nowrap;
@@ -166,9 +175,9 @@
     min-width: 0;
     height: 36px;
     padding: 0 6px 0 10px;
-    border: 1px solid rgba(255, 255, 255, 0.1);
+    border: 1px solid transparent;
     border-radius: 10px;
-    background: rgba(255, 255, 255, 0.07);
+    background: rgba(255, 255, 255, 0.06);
     cursor: text;
     transition:
         border-color 150ms ease-out,
@@ -176,7 +185,7 @@
 }
 
 .fullscreen-channel-panel__search:focus-within {
-    border-color: var(--app-selection-color, #78adff);
+    border-color: rgba(255, 255, 255, 0.28);
     background: rgba(255, 255, 255, 0.1);
 }
 
@@ -217,7 +226,7 @@
     height: 26px;
     padding: 0;
     border: 0;
-    border-radius: 50%;
+    border-radius: 8px;
     color: rgba(255, 255, 255, 0.75);
     background: transparent;
     cursor: pointer;
@@ -226,7 +235,7 @@
 .fullscreen-channel-panel__search-clear:hover,
 .fullscreen-channel-panel__search-clear:focus-visible {
     color: #ffffff;
-    background: rgba(255, 255, 255, 0.14);
+    background: rgba(255, 255, 255, 0.1);
 }
 
 .fullscreen-channel-panel__search-clear mat-icon {
@@ -235,15 +244,31 @@
     font-size: 18px;
 }
 
+// The settings panel's close button: a 32px, 10px-cornered square with a flat
+// hover fill instead of Material's round state layer.
 .fullscreen-channel-panel__close {
     flex-shrink: 0;
-    color: rgba(255, 255, 255, 0.8);
+    width: 32px;
+    height: 32px;
+    padding: 4px;
+    border-radius: 10px;
+    color: #e7ecf3;
     --mdc-icon-button-icon-color: currentColor;
     --mat-icon-button-icon-color: currentColor;
+    --mat-icon-button-state-layer-size: 32px;
+    --mat-icon-button-container-shape: 10px;
+    --mat-icon-button-icon-size: 20px;
+    --mat-icon-button-hover-state-layer-opacity: 0;
+}
+
+.fullscreen-channel-panel__close mat-icon {
+    width: 20px;
+    height: 20px;
+    font-size: 20px;
 }
 
 .fullscreen-channel-panel__close:hover {
-    color: #ffffff;
+    background: rgba(255, 255, 255, 0.1);
 }
 
 // ─── Body ────────────────────────────────────────────────────────────────────
@@ -278,7 +303,11 @@
 
 @container (max-width: 560px) {
     .fullscreen-channel-panel {
-        width: calc(100% - 44px);
+        top: 8px;
+        bottom: 8px;
+        left: 8px;
+        width: calc(100% - 52px);
+        border-radius: 16px;
     }
 }
 

libs/ui/playback/src/lib/fullscreen-episode-panel/fullscreen-episode-panel.component.scss

@@ -121,6 +121,11 @@
         background: rgba(255, 255, 255, 0.1);
     }
 
+    &:focus-visible {
+        outline: 2px solid #e7ecf3;
+        outline-offset: -2px;
+    }
+
     mat-icon {
         width: 16px;
         height: 16px;
@@ -152,13 +157,15 @@
     }
 
     &:focus-visible {
-        outline: 2px solid var(--app-selection-color, #78adff);
+        outline: 2px solid #e7ecf3;
         outline-offset: -2px;
     }
 }
 
+// The playing row wears the settings panel's selected-option tint: cyan means
+// "this is on" across the player chrome.
 .episode-panel__item--playing {
-    background: rgba(255, 255, 255, 0.14);
+    background: rgba(92, 214, 255, 0.14);
     cursor: default;
 }
 
@@ -266,7 +273,7 @@
     font-size: 0.62rem;
     letter-spacing: 0.14em;
     text-transform: uppercase;
-    color: #7dd87d;
+    color: #5cd6ff;
 }
 
 .episode-panel__title {