feat(engine): duck the glass tab bar during card drags

While a drag is committed the floating bar slides below the screen
edge (UiTransform translation - no layout dirtying, no fight with the
safe-area anchor over Node::bottom) so it never occludes a drop target
on the bottom tableau rows; it slides back on release. Same tween rate
as the label reveal, snaps under reduce-motion. Desktop docked bar is
untouched (no TabBarDuck component).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

CHANGELOG.md

@@ -6,6 +6,47 @@ project follows [Semantic Versioning](https://semver.org/).
 
 ## [Unreleased]
 
+## [0.48.0] — 2026-07-15
+
+### Changed
+
+- **Floating glass tab bar** (touch). The bottom action bar is now a
+  floating translucent pill — Undo, Draw, Hint, and Pause — with a
+  separate round Menu button beside it, hovering above the bottom edge
+  instead of docking to it. Draw stays expanded as the highlighted
+  action; the other buttons reveal their label while held (instantly,
+  with reduce-motion on). Same actions, same behaviour — new clothes.
+  (#186)
+- **Consistent empty, loading, and error screens.** The theme store,
+  leaderboard, and replay list now share one visual language for
+  "nothing here yet", "still loading", and "something went wrong" —
+  each with a next step instead of a dead end. (#184)
+
+### Fixed
+
+- **Hotkeys during drags.** Pressing Undo, New Game, Draw, or a mode
+  key mid-drag no longer fights the card you're holding — game-mutating
+  hotkeys are ignored until the card is dropped. (#185)
+
+## [0.47.0] — 2026-07-13
+
+### Added
+
+- **"What's new" on update.** The first launch after an update shows a
+  one-time card summarising what changed — like this one, right now.
+  Dismiss it and it never repeats; fresh installs never see it. (#180)
+- **Situational tips.** Two one-time teaches that fire from play, not a
+  tour: staring at a stuck board for a while points you at Hint, and an
+  engaged game quietly mentions the long-press quick-action menu —
+  unless you've already found it yourself. (#181)
+- **UI scale.** Settings → Accessibility now has a UI Scale control
+  (90% / 100% / 115% / 130%) that resizes every menu, button, and HUD
+  element live. The table always fits your screen regardless. (#182)
+- **Hold `/` for shortcuts** (desktop). A reference card of every
+  keyboard binding appears while `/` is held. The onboarding tour and
+  this card now share one binding table, so they can never disagree —
+  the tour's copy had drifted from reality. (#183)
+
 ## [0.46.0] — 2026-07-13
 
 ### Added

solitaire_data/src/settings.rs

@@ -154,6 +154,14 @@ pub struct Settings {
     /// `#[serde(default)]`.
     #[serde(default)]
     pub reduce_motion_mode: bool,
+    /// When `true`, replaces translucent "glass" chrome (the floating
+    /// touch tab bar) with opaque fills so table content behind it can
+    /// never reduce label/icon contrast. The accessibility counterpart
+    /// of iOS "Reduce Transparency". Older `settings.json` files written
+    /// before this field existed deserialize cleanly to `false` thanks
+    /// to `#[serde(default)]`.
+    #[serde(default)]
+    pub reduce_transparency_mode: bool,
     /// Window size and screen position to restore on next launch. `None`
     /// means "use platform defaults" — set on first run, then populated
     /// as the player resizes / moves the window. Older `settings.json`
@@ -265,6 +273,24 @@ pub struct Settings {
     /// `#[serde(default)]`.
     #[serde(default)]
     pub last_seen_whats_new: String,
+    /// `true` once the one-shot "Stuck? Try a hint" contextual tip has
+    /// fired (or been suppressed as unnecessary). Phase I teach: fired
+    /// by the situation, shown once, like `shown_achievement_onboarding`.
+    #[serde(default)]
+    pub shown_stall_hint_tip: bool,
+    /// `true` once the one-shot radial-menu contextual tip has fired —
+    /// or the player has already opened the radial menu on their own,
+    /// which marks the tip as unnecessary without showing it.
+    #[serde(default)]
+    pub shown_radial_menu_tip: bool,
+    /// Global UI scale multiplier applied to all UI chrome (HUD, modals,
+    /// action bar) — the table itself stays window-fit via
+    /// `compute_layout`. Cycles through 0.9 / 1.0 / 1.15 / 1.3 in
+    /// Settings → Accessibility; clamped to `[UI_SCALE_MIN,
+    /// UI_SCALE_MAX]` by [`Settings::sanitized`]. Older `settings.json`
+    /// files deserialize cleanly to `1.0` via the serde default.
+    #[serde(default = "default_ui_scale")]
+    pub ui_scale: f32,
     /// Custom public name displayed on the leaderboard. When `None`, the
     /// player's server `username` is used instead. Trimmed to 32 characters
     /// before submission. Older `settings.json` files written before this
@@ -373,6 +399,16 @@ fn default_replay_move_interval_secs() -> f32 {
     0.45
 }
 
+/// Lowest / highest UI scale the settings row offers; anything outside
+/// (hand-edited settings.json) clamps here on load.
+pub const UI_SCALE_MIN: f32 = 0.9;
+/// See [`UI_SCALE_MIN`].
+pub const UI_SCALE_MAX: f32 = 1.3;
+
+fn default_ui_scale() -> f32 {
+    1.0
+}
+
 fn default_matomo_site_id() -> u32 {
     1
 }
@@ -423,6 +459,7 @@ impl Default for Settings {
             color_blind_mode: false,
             high_contrast_mode: false,
             reduce_motion_mode: false,
+            reduce_transparency_mode: false,
             window_geometry: None,
             selected_theme_id: default_theme_id(),
             shown_achievement_onboarding: false,
@@ -434,6 +471,9 @@ impl Default for Settings {
             last_difficulty: None,
             last_mode: GameMode::Classic,
             last_seen_whats_new: String::new(),
+            shown_stall_hint_tip: false,
+            shown_radial_menu_tip: false,
+            ui_scale: default_ui_scale(),
             leaderboard_display_name: None,
             leaderboard_opted_in: false,
             take_from_foundation: true,
@@ -469,6 +509,7 @@ impl Settings {
             replay_move_interval_secs: self
                 .replay_move_interval_secs
                 .clamp(REPLAY_MOVE_INTERVAL_MIN_SECS, REPLAY_MOVE_INTERVAL_MAX_SECS),
+            ui_scale: self.ui_scale.clamp(UI_SCALE_MIN, UI_SCALE_MAX),
             selected_theme_id,
             ..self
         }

solitaire_engine/src/animation_plugin.rs

@@ -179,10 +179,13 @@ pub struct ToastStackRoot;
 pub struct ToastNode;
 
 /// Logical-pixel gap between the screen bottom and the toast stack,
-/// before safe-area insets. Clears the Phase F bottom action bar on
-/// touch (compact 44px buttons + primary 64px trio + bar padding);
-/// desktop's shorter bar needs less.
-const TOAST_STACK_BASE_BOTTOM_PX: f32 = if USE_TOUCH_UI_LAYOUT { 112.0 } else { 72.0 };
+/// before safe-area insets. Clears the floating glass tab bar on touch
+/// (its margin + height + breathing room); desktop's docked bar needs less.
+const TOAST_STACK_BASE_BOTTOM_PX: f32 = if USE_TOUCH_UI_LAYOUT {
+    crate::hud_plugin::tab_bar::TAB_BAR_CLEARANCE_PX
+} else {
+    72.0
+};
 
 /// Spawns the persistent [`ToastStackRoot`] container at startup.
 fn spawn_toast_stack_root(mut commands: Commands) {

solitaire_engine/src/assets/hud_icon_svg.rs

@@ -0,0 +1,127 @@
+//! SVG builders for the floating tab bar's action icons.
+//!
+//! The touch tab bar (`hud_plugin::tab_bar`) is icon-first, but the bundled
+//! FiraMono face has no icon glyphs (and the Geometric Shapes block U+25xx
+//! is missing on Android entirely), so the icons are authored here as tiny
+//! stroke-based SVGs and rasterised through the same `usvg`/`resvg` pipeline
+//! as the card themes (`assets::rasterize_svg`).
+//!
+//! Icons are drawn in **white** on a transparent background inside a
+//! 24-unit logical box; the spawn site tints them to the theme colour via
+//! `ImageNode::color` (a per-node multiply), so one texture serves every
+//! button state.
+
+use bevy::image::Image;
+use bevy::math::UVec2;
+
+use super::svg_loader::{SvgLoaderError, rasterize_svg};
+
+/// Rasterisation size for one tab-bar icon texture. Icons display at
+/// 24 logical px; 96 px texels keep them crisp at the Fold's 1.2 scale
+/// factor (and any future 3× phone) while staying trivially small.
+pub const HUD_ICON_TEXTURE_PX: u32 = 96;
+
+/// The five actions the floating touch tab bar can show.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum HudIcon {
+    /// Counter-clockwise "take back" arrow.
+    Undo,
+    /// Two offset card outlines — draw from the stock.
+    Draw,
+    /// Lightbulb — highlight a suggested move.
+    Hint,
+    /// Two vertical bars.
+    Pause,
+    /// Three-line hamburger — the floating menu button.
+    Menu,
+}
+
+impl HudIcon {
+    /// Build the icon's SVG document. All icons share one visual language:
+    /// 2-unit white strokes, round caps, transparent fill, 24-unit box.
+    pub fn svg(self) -> String {
+        let body = match self {
+            // Arrow head pointing left into a half-circle sweeping back
+            // over the top — the conventional undo mark.
+            HudIcon::Undo => concat!(
+                r##"<path d="M 8 5 L 4 9 L 8 13"/>"##,
+                r##"<path d="M 4 9 H 14 A 5.5 5.5 0 0 1 14 20 H 8"/>"##,
+            ),
+            // Back card peeks out behind the front card; the front card is
+            // drawn second so its stroke reads on top.
+            HudIcon::Draw => concat!(
+                r##"<rect x="8.5" y="3" width="11" height="15" rx="2"/>"##,
+                r##"<rect x="4" y="6.5" width="11" height="15" rx="2"/>"##,
+            ),
+            // Bulb dome with a flat lamp base beneath.
+            HudIcon::Hint => concat!(
+                r##"<path d="M 9 15.5 A 6.5 6.5 0 1 1 15 15.5 V 18 H 9 Z"/>"##,
+                r##"<path d="M 10 21 H 14"/>"##,
+            ),
+            HudIcon::Pause => concat!(
+                r##"<path d="M 9 6 V 18"/>"##,
+                r##"<path d="M 15 6 V 18"/>"##,
+            ),
+            HudIcon::Menu => concat!(
+                r##"<path d="M 4 6.5 H 20"/>"##,
+                r##"<path d="M 4 12 H 20"/>"##,
+                r##"<path d="M 4 17.5 H 20"/>"##,
+            ),
+        };
+        format!(
+            concat!(
+                r##"<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24">"##,
+                r##"<g fill="none" stroke="#ffffff" stroke-width="2" "##,
+                r##"stroke-linecap="round" stroke-linejoin="round">{body}</g>"##,
+                r##"</svg>"##,
+            ),
+            body = body
+        )
+    }
+
+    /// Rasterise this icon into a Bevy [`Image`] at
+    /// [`HUD_ICON_TEXTURE_PX`] square.
+    pub fn rasterize(self) -> Result<Image, SvgLoaderError> {
+        rasterize_svg(self.svg().as_bytes(), UVec2::splat(HUD_ICON_TEXTURE_PX))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const ALL: [HudIcon; 5] = [
+        HudIcon::Undo,
+        HudIcon::Draw,
+        HudIcon::Hint,
+        HudIcon::Pause,
+        HudIcon::Menu,
+    ];
+
+    /// Every icon must survive the real usvg/resvg pipeline at the real
+    /// texture size — a malformed path here would otherwise only surface
+    /// as a blank button on device.
+    #[test]
+    fn every_icon_rasterizes_at_texture_size() {
+        for icon in ALL {
+            let img = icon.rasterize().expect("icon SVG must rasterise");
+            assert_eq!(img.width(), HUD_ICON_TEXTURE_PX, "{icon:?} width");
+            assert_eq!(img.height(), HUD_ICON_TEXTURE_PX, "{icon:?} height");
+        }
+    }
+
+    /// Rasterised icons must contain visible (non-transparent) pixels —
+    /// guards against a stroke accidentally drawn outside the viewBox.
+    #[test]
+    fn every_icon_has_visible_pixels() {
+        for icon in ALL {
+            let img = icon.rasterize().expect("icon SVG must rasterise");
+            let data = img.data.as_ref().expect("rasterised image has data");
+            let opaque = data.chunks_exact(4).filter(|px| px[3] > 0).count();
+            assert!(
+                opaque > 100,
+                "{icon:?} renders only {opaque} visible pixels"
+            );
+        }
+    }
+}

solitaire_engine/src/assets/mod.rs

@@ -5,6 +5,7 @@
 //! custom `AssetSource` implementations used by the theme system.
 
 pub mod card_face_svg;
+pub mod hud_icon_svg;
 pub mod icon_svg;
 pub mod sources;
 pub mod svg_loader;

solitaire_engine/src/cheat_sheet_plugin.rs

@@ -0,0 +1,194 @@
+//! Hold-`/` hotkey cheat sheet (Phase J).
+//!
+//! While `/` is held on a keyboard platform, a lightweight overlay
+//! lists every binding from [`crate::hotkeys::HOTKEYS`] — the same
+//! table the onboarding slide teaches from, so the two can never
+//! disagree. Releasing the key hides it instantly; it never captures
+//! input, never pauses the game, and never spawns while a modal owns
+//! the screen (which also keeps it out of the seed-entry text field's
+//! way).
+//!
+//! Not a `spawn_modal` modal on purpose: modals are sticky and guarded;
+//! this is a momentary reference card, closer to a tooltip than a
+//! dialog.
+
+use bevy::input::ButtonInput;
+use bevy::prelude::*;
+
+use crate::font_plugin::FontResource;
+use crate::hotkeys::HOTKEYS;
+use crate::platform::SHOW_KEYBOARD_ACCELERATORS;
+use crate::ui_modal::ModalScrim;
+use crate::ui_theme::{
+    ACCENT_PRIMARY, BG_ELEVATED, BORDER_STRONG, HighContrastBorder, RADIUS_MD, TEXT_PRIMARY,
+    TEXT_SECONDARY, TYPE_BODY, TYPE_CAPTION, VAL_SPACE_1, VAL_SPACE_2, VAL_SPACE_3, VAL_SPACE_4,
+    Z_TOOLTIP,
+};
+
+/// Marker on the cheat-sheet overlay root.
+#[derive(Component, Debug)]
+pub struct CheatSheetOverlay;
+
+/// Registers the hold-`/` driver. Inert on touch-first builds.
+pub struct CheatSheetPlugin;
+
+impl Plugin for CheatSheetPlugin {
+    fn build(&self, app: &mut App) {
+        app.init_resource::<ButtonInput<KeyCode>>()
+            .add_systems(Update, drive_cheat_sheet);
+    }
+}
+
+/// Shows the overlay while `/` is held (and no modal owns the screen);
+/// hides it the frame the key releases.
+fn drive_cheat_sheet(
+    keys: Res<ButtonInput<KeyCode>>,
+    scrims: Query<(), With<ModalScrim>>,
+    existing: Query<Entity, With<CheatSheetOverlay>>,
+    font_res: Option<Res<FontResource>>,
+    mut commands: Commands,
+) {
+    if !SHOW_KEYBOARD_ACCELERATORS {
+        return;
+    }
+    let held = keys.pressed(KeyCode::Slash);
+    if held && existing.is_empty() && scrims.is_empty() {
+        spawn_cheat_sheet(&mut commands, font_res.as_deref());
+    } else if !held {
+        for entity in &existing {
+            commands.entity(entity).despawn();
+        }
+    }
+}
+
+fn spawn_cheat_sheet(commands: &mut Commands, font_res: Option<&FontResource>) {
+    let font_handle = font_res.map(|f| f.0.clone()).unwrap_or_default();
+    let font_header = TextFont {
+        font: font_handle.clone(),
+        font_size: TYPE_BODY,
+        ..default()
+    };
+    let font_keys = TextFont {
+        font: font_handle.clone(),
+        font_size: TYPE_CAPTION,
+        ..default()
+    };
+    let font_desc = TextFont {
+        font: font_handle,
+        font_size: TYPE_CAPTION,
+        ..default()
+    };
+
+    commands
+        .spawn((
+            CheatSheetOverlay,
+            Node {
+                position_type: PositionType::Absolute,
+                right: Val::Px(16.0),
+                top: Val::Percent(8.0),
+                flex_direction: FlexDirection::Column,
+                row_gap: VAL_SPACE_1,
+                padding: UiRect::all(VAL_SPACE_4),
+                border: UiRect::all(Val::Px(1.0)),
+                border_radius: BorderRadius::all(Val::Px(RADIUS_MD)),
+                max_height: Val::Percent(84.0),
+                overflow: Overflow::scroll_y(),
+                ..default()
+            },
+            BackgroundColor(BG_ELEVATED),
+            BorderColor::all(BORDER_STRONG),
+            HighContrastBorder::with_default(BORDER_STRONG),
+            GlobalZIndex(Z_TOOLTIP),
+        ))
+        .with_children(|panel| {
+            panel.spawn((
+                Text::new("Keyboard shortcuts"),
+                font_header.clone(),
+                TextColor(TEXT_PRIMARY),
+                Node {
+                    margin: UiRect::bottom(VAL_SPACE_2),
+                    ..default()
+                },
+            ));
+            for row in HOTKEYS {
+                panel
+                    .spawn(Node {
+                        flex_direction: FlexDirection::Row,
+                        column_gap: VAL_SPACE_3,
+                        ..default()
+                    })
+                    .with_children(|line| {
+                        line.spawn((
+                            Text::new(row.keys),
+                            font_keys.clone(),
+                            TextColor(ACCENT_PRIMARY),
+                            Node {
+                                min_width: Val::Px(110.0),
+                                ..default()
+                            },
+                        ));
+                        line.spawn((
+                            Text::new(row.description),
+                            font_desc.clone(),
+                            TextColor(TEXT_SECONDARY),
+                        ));
+                    });
+            }
+        });
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn app() -> App {
+        let mut app = App::new();
+        app.add_plugins(MinimalPlugins)
+            .add_plugins(CheatSheetPlugin);
+        app.update();
+        app
+    }
+
+    fn overlay_count(app: &mut App) -> usize {
+        app.world_mut()
+            .query::<&CheatSheetOverlay>()
+            .iter(app.world())
+            .count()
+    }
+
+    #[test]
+    fn holding_slash_shows_and_release_hides() {
+        let mut app = app();
+        app.world_mut()
+            .resource_mut::<ButtonInput<KeyCode>>()
+            .press(KeyCode::Slash);
+        app.update();
+        assert_eq!(overlay_count(&mut app), 1, "held / must show the sheet");
+        // Still held on later frames: exactly one overlay, no stacking.
+        app.update();
+        assert_eq!(overlay_count(&mut app), 1);
+
+        app.world_mut()
+            .resource_mut::<ButtonInput<KeyCode>>()
+            .release(KeyCode::Slash);
+        app.update();
+        app.update();
+        assert_eq!(overlay_count(&mut app), 0, "release must hide the sheet");
+    }
+
+    #[test]
+    fn suppressed_while_a_modal_is_open() {
+        let mut app = app();
+        app.world_mut().spawn(ModalScrim);
+        app.update();
+        app.world_mut()
+            .resource_mut::<ButtonInput<KeyCode>>()
+            .press(KeyCode::Slash);
+        app.update();
+        assert_eq!(
+            overlay_count(&mut app),
+            0,
+            "the sheet must not spawn over a modal (or into a text field)"
+        );
+    }
+}

solitaire_engine/src/contextual_tips_plugin.rs

@@ -0,0 +1,309 @@
+//! Contextual one-time tips (Phase I of the 2026-07 UI redesign).
+//!
+//! Everything the first-run onboarding doesn't cover is invisible until
+//! stumbled upon: hint cycling, the radial quick-action menu. These
+//! tips fire **from the situation, not a tour** — each exactly once,
+//! recorded in `Settings` like `shown_achievement_onboarding`:
+//!
+//! - **Stall tip** — after [`STALL_TIP_SECS`] with no board change in an
+//!   active game, an info toast points at Hint. A player staring at a
+//!   stuck board is the one moment the tip is welcome.
+//! - **Radial tip** — once a game reaches [`RADIAL_TIP_MIN_MOVES`] moves
+//!   (an engaged player) and the radial menu has never been opened, an
+//!   info toast teaches the long-press / right-click gesture. Opening
+//!   the radial organically marks the tip as unnecessary — it is never
+//!   shown to someone who already knows.
+//!
+//! Tips render through the queued [`InfoToastEvent`] path, so they share
+//! the unified toast stack and never interrupt play.
+
+use bevy::prelude::*;
+
+use solitaire_data::save_settings_to;
+
+use crate::events::{InfoToastEvent, StateChangedEvent};
+use crate::game_plugin::GameMutation;
+use crate::pause_plugin::PausedResource;
+use crate::platform::SHOW_KEYBOARD_ACCELERATORS;
+use crate::radial_menu::RightClickRadialState;
+use crate::resources::GameStateResource;
+use crate::settings_plugin::{SettingsResource, SettingsStoragePath};
+use crate::ui_modal::ModalScrim;
+
+/// Seconds without any board change before the stall tip fires.
+/// Long enough that normal thinking never triggers it; short enough to
+/// reach a genuinely stuck player before they quit.
+const STALL_TIP_SECS: f32 = 45.0;
+
+/// Move count at which an engaged player earns the radial-menu teach.
+const RADIAL_TIP_MIN_MOVES: u32 = 15;
+
+/// Stall-tip copy per platform input vocabulary.
+const STALL_TIP: &str = if SHOW_KEYBOARD_ACCELERATORS {
+    "Stuck? Press H for a hint."
+} else {
+    "Stuck? Tap Hint in the bottom bar for a suggested move."
+};
+
+/// Radial-tip copy per platform input vocabulary.
+const RADIAL_TIP: &str = if SHOW_KEYBOARD_ACCELERATORS {
+    "Tip: right-click a card for quick actions."
+} else {
+    "Tip: long-press a card for quick actions."
+};
+
+/// Seconds of board inactivity, frozen while paused / a modal is open,
+/// reset by every [`StateChangedEvent`].
+#[derive(Resource, Debug, Default)]
+pub struct StallClock(pub f32);
+
+/// Registers the stall clock and the two tip triggers.
+pub struct ContextualTipsPlugin;
+
+impl Plugin for ContextualTipsPlugin {
+    fn build(&self, app: &mut App) {
+        app.init_resource::<StallClock>()
+            .add_message::<InfoToastEvent>()
+            .add_message::<StateChangedEvent>()
+            .add_systems(
+                Update,
+                (
+                    tick_stall_clock,
+                    fire_stall_hint_tip
+                        .in_set(crate::game_plugin::InfoToastWriters)
+                        .ambiguous_with(crate::game_plugin::InfoToastWriters),
+                    observe_radial_menu_use,
+                    fire_radial_menu_tip
+                        .in_set(crate::game_plugin::InfoToastWriters)
+                        .ambiguous_with(crate::game_plugin::InfoToastWriters),
+                )
+                    .chain()
+                    .after(GameMutation),
+            );
+    }
+}
+
+/// Advances the stall clock; resets on any board change; freezes while
+/// paused, while a modal owns the screen, or when the game is over.
+fn tick_stall_clock(
+    time: Res<Time>,
+    mut state_events: MessageReader<StateChangedEvent>,
+    paused: Option<Res<PausedResource>>,
+    scrims: Query<(), With<ModalScrim>>,
+    game: Option<Res<GameStateResource>>,
+    mut clock: ResMut<StallClock>,
+) {
+    if state_events.read().next().is_some() {
+        clock.0 = 0.0;
+        return;
+    }
+    if paused.is_some_and(|p| p.0)
+        || !scrims.is_empty()
+        || game.as_ref().is_none_or(|g| g.0.is_won())
+    {
+        // Frozen, not reset: backgrounding into a menu mid-stall
+        // shouldn't restart the wait.
+        return;
+    }
+    clock.0 += time.delta_secs();
+}
+
+/// Fires the one-shot stall tip once the clock passes the threshold in
+/// a game the player has actually started (at least one move).
+fn fire_stall_hint_tip(
+    clock: Res<StallClock>,
+    game: Option<Res<GameStateResource>>,
+    mut settings: Option<ResMut<SettingsResource>>,
+    storage_path: Option<Res<SettingsStoragePath>>,
+    mut toast: MessageWriter<InfoToastEvent>,
+) {
+    let Some(s) = settings.as_mut() else { return };
+    if s.0.shown_stall_hint_tip || clock.0 < STALL_TIP_SECS {
+        return;
+    }
+    if game
+        .as_ref()
+        .is_none_or(|g| g.0.move_count() == 0 || g.0.is_won())
+    {
+        return;
+    }
+    toast.write(InfoToastEvent(STALL_TIP.to_string()));
+    s.0.shown_stall_hint_tip = true;
+    persist(storage_path.as_deref(), &s.0);
+}
+
+/// A player who opens the radial menu on their own doesn't need the
+/// teach — mark the tip done silently.
+fn observe_radial_menu_use(
+    radial: Option<Res<RightClickRadialState>>,
+    mut settings: Option<ResMut<SettingsResource>>,
+    storage_path: Option<Res<SettingsStoragePath>>,
+) {
+    let Some(radial) = radial else { return };
+    if !radial.is_active() {
+        return;
+    }
+    let Some(s) = settings.as_mut() else { return };
+    if s.0.shown_radial_menu_tip {
+        return;
+    }
+    s.0.shown_radial_menu_tip = true;
+    persist(storage_path.as_deref(), &s.0);
+}
+
+/// Fires the one-shot radial teach for an engaged player who has never
+/// opened the menu themselves.
+fn fire_radial_menu_tip(
+    game: Option<Res<GameStateResource>>,
+    mut settings: Option<ResMut<SettingsResource>>,
+    storage_path: Option<Res<SettingsStoragePath>>,
+    mut toast: MessageWriter<InfoToastEvent>,
+) {
+    let Some(s) = settings.as_mut() else { return };
+    if s.0.shown_radial_menu_tip {
+        return;
+    }
+    if game
+        .as_ref()
+        .is_none_or(|g| g.0.move_count() < RADIAL_TIP_MIN_MOVES || g.0.is_won())
+    {
+        return;
+    }
+    toast.write(InfoToastEvent(RADIAL_TIP.to_string()));
+    s.0.shown_radial_menu_tip = true;
+    persist(storage_path.as_deref(), &s.0);
+}
+
+fn persist(storage_path: Option<&SettingsStoragePath>, settings: &solitaire_data::Settings) {
+    if let Some(p) = storage_path
+        && let Some(path) = p.0.as_deref()
+        && let Err(e) = save_settings_to(path, settings)
+    {
+        warn!("contextual tips: failed to persist tip flag: {e}");
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use bevy::ecs::message::Messages;
+    use solitaire_core::{DrawStockConfig, game_state::GameState};
+    use solitaire_data::Settings;
+
+    fn app_with(settings: Settings, game: GameState) -> App {
+        let mut app = App::new();
+        app.add_plugins(MinimalPlugins)
+            .add_plugins(ContextualTipsPlugin);
+        app.insert_resource(SettingsResource(settings));
+        app.insert_resource(GameStateResource(game));
+        app.update();
+        app
+    }
+
+    fn info_toast_count(app: &App) -> usize {
+        let events = app.world().resource::<Messages<InfoToastEvent>>();
+        let mut cursor = events.get_cursor();
+        cursor.read(events).count()
+    }
+
+    fn started_game() -> GameState {
+        let mut game = GameState::new(7, DrawStockConfig::DrawOne);
+        game.draw().expect("draw from fresh deal");
+        game
+    }
+
+    #[test]
+    fn stall_tip_fires_once_past_threshold() {
+        let mut app = app_with(Settings::default(), started_game());
+        app.world_mut().resource_mut::<StallClock>().0 = STALL_TIP_SECS + 1.0;
+        app.update();
+
+        assert_eq!(info_toast_count(&app), 1, "stall tip must fire");
+        assert!(
+            app.world()
+                .resource::<SettingsResource>()
+                .0
+                .shown_stall_hint_tip,
+            "the tip flag must set so it never repeats"
+        );
+
+        app.world_mut().resource_mut::<StallClock>().0 = STALL_TIP_SECS + 30.0;
+        app.world_mut()
+            .resource_mut::<Messages<InfoToastEvent>>()
+            .clear();
+        app.update();
+        assert_eq!(info_toast_count(&app), 0, "the tip is one-shot");
+    }
+
+    #[test]
+    fn stall_tip_needs_a_started_unwon_game() {
+        // Untouched deal: staring at the launch screen is not a stall.
+        let mut app = app_with(
+            Settings::default(),
+            GameState::new(7, DrawStockConfig::DrawOne),
+        );
+        app.world_mut().resource_mut::<StallClock>().0 = STALL_TIP_SECS + 1.0;
+        app.update();
+        assert_eq!(info_toast_count(&app), 0, "no tip on an untouched deal");
+
+        // Won game: nothing to hint at.
+        let mut won = started_game();
+        won.set_test_won(true);
+        let mut app = app_with(Settings::default(), won);
+        app.world_mut().resource_mut::<StallClock>().0 = STALL_TIP_SECS + 1.0;
+        app.update();
+        assert_eq!(info_toast_count(&app), 0, "no tip on a won game");
+    }
+
+    #[test]
+    fn stall_clock_resets_on_state_change() {
+        let mut app = app_with(Settings::default(), started_game());
+        app.world_mut().resource_mut::<StallClock>().0 = 30.0;
+        app.world_mut().write_message(StateChangedEvent);
+        app.update();
+        assert_eq!(
+            app.world().resource::<StallClock>().0,
+            0.0,
+            "any board change must reset the stall clock"
+        );
+    }
+
+    #[test]
+    fn radial_tip_fires_for_engaged_player() {
+        let mut game = started_game();
+        game.set_test_move_count(RADIAL_TIP_MIN_MOVES);
+        let mut app = app_with(Settings::default(), game);
+        app.update();
+
+        assert_eq!(
+            info_toast_count(&app),
+            1,
+            "radial tip must fire at the move threshold"
+        );
+        assert!(
+            app.world()
+                .resource::<SettingsResource>()
+                .0
+                .shown_radial_menu_tip
+        );
+    }
+
+    #[test]
+    fn radial_tip_suppressed_after_organic_use() {
+        let mut game = started_game();
+        game.set_test_move_count(RADIAL_TIP_MIN_MOVES);
+        let mut app = app_with(
+            Settings {
+                shown_radial_menu_tip: true,
+                ..Settings::default()
+            },
+            game,
+        );
+        app.update();
+        assert_eq!(
+            info_toast_count(&app),
+            0,
+            "a player who used the radial menu never sees the teach"
+        );
+    }
+}

solitaire_engine/src/core_game_plugin.rs

@@ -14,14 +14,14 @@ use crate::platform::{
 };
 use crate::{
     AchievementPlugin, AnimationPlugin, AssetSourcesPlugin, AutoCompletePlugin,
-    CardAnimationPlugin, CardPlugin, ChallengePlugin, CursorPlugin, DailyChallengePlugin,
-    DiagnosticsHudPlugin, DifficultyPlugin, FeedbackAnimPlugin, FontPlugin, GamePlugin, HelpPlugin,
-    HomePlugin, HudPlugin, InputPlugin, OnboardingPlugin, PausePlugin, PlayBySeedPlugin,
-    ProfilePlugin, ProgressPlugin, RadialMenuPlugin, ReplayOverlayPlugin, ReplayPlaybackPlugin,
-    SafeAreaInsetsPlugin, SelectionPlugin, SettingsPlugin, SolutionPlaybackPlugin, SplashPlugin,
-    StatsPlugin, SyncProvider, TablePlugin, ThemePlugin, ThemeRegistryPlugin, TimeAttackPlugin,
-    TouchSelectionPlugin, UiFocusPlugin, UiModalPlugin, UiTooltipPlugin, WeeklyGoalsPlugin,
-    WhatsNewPlugin, WinSummaryPlugin,
+    CardAnimationPlugin, CardPlugin, ChallengePlugin, CheatSheetPlugin, ContextualTipsPlugin,
+    CursorPlugin, DailyChallengePlugin, DiagnosticsHudPlugin, DifficultyPlugin, FeedbackAnimPlugin,
+    FontPlugin, GamePlugin, HelpPlugin, HomePlugin, HudPlugin, InputPlugin, OnboardingPlugin,
+    PausePlugin, PlayBySeedPlugin, ProfilePlugin, ProgressPlugin, RadialMenuPlugin,
+    ReplayOverlayPlugin, ReplayPlaybackPlugin, SafeAreaInsetsPlugin, SelectionPlugin,
+    SettingsPlugin, SolutionPlaybackPlugin, SplashPlugin, StatsPlugin, SyncProvider, TablePlugin,
+    ThemePlugin, ThemeRegistryPlugin, TimeAttackPlugin, TouchSelectionPlugin, UiFocusPlugin,
+    UiModalPlugin, UiTooltipPlugin, WeeklyGoalsPlugin, WhatsNewPlugin, WinSummaryPlugin,
 };
 #[cfg(not(target_arch = "wasm32"))]
 use crate::{
@@ -116,6 +116,8 @@ impl Plugin for CoreGamePlugin {
             .add_plugins(SettingsPlugin::default())
             .add_plugins(OnboardingPlugin)
             .add_plugins(WhatsNewPlugin)
+            .add_plugins(ContextualTipsPlugin)
+            .add_plugins(CheatSheetPlugin)
             .add_plugins(WinSummaryPlugin)
             .add_plugins(UiModalPlugin)
             .add_plugins(UiFocusPlugin)

solitaire_engine/src/hotkeys.rs

@@ -0,0 +1,169 @@
+//! Single source of truth for the desktop keyboard bindings (Phase J).
+//!
+//! Two static hotkey tables had already diverged (onboarding's slide
+//! and Help's controls reference); every future drift multiplies. This
+//! module owns THE table: the onboarding slide renders the
+//! [`HotkeyRow::essential`] subset, the hold-`/` cheat sheet
+//! ([`crate::cheat_sheet_plugin`]) renders everything.
+//!
+//! The table is hand-maintained but **pinned by test** against the
+//! handlers that actually consume each key — adding a binding without
+//! updating this table (or vice versa) is designed to fail review, not
+//! runtime. A registry generated from the input systems themselves is
+//! the eventual ideal; this is the honest 90 % at 1 % of the cost.
+
+/// One row of the hotkey table.
+#[derive(Debug, Clone, Copy)]
+pub struct HotkeyRow {
+    /// Display form of the key(s), e.g. `"D / Space"`.
+    pub keys: &'static str,
+    /// One-line action description.
+    pub description: &'static str,
+    /// `true` for the beginner-relevant subset the onboarding slide
+    /// shows; the cheat sheet always shows every row.
+    pub essential: bool,
+}
+
+/// Every desktop keyboard binding, in teaching order.
+pub const HOTKEYS: &[HotkeyRow] = &[
+    HotkeyRow {
+        keys: "D / Space",
+        description: "Draw from stock",
+        essential: true,
+    },
+    HotkeyRow {
+        keys: "U",
+        description: "Undo last move (hold to repeat)",
+        essential: true,
+    },
+    HotkeyRow {
+        keys: "H",
+        description: "Hint (repeat to cycle alternatives)",
+        essential: true,
+    },
+    HotkeyRow {
+        keys: "Tab → Enter",
+        description: "Pick a card; arrows pick where; Enter to drop",
+        essential: true,
+    },
+    HotkeyRow {
+        keys: "N",
+        description: "New Classic game",
+        essential: true,
+    },
+    HotkeyRow {
+        keys: "M",
+        description: "Open Home (then 1–6 to pick a mode)",
+        essential: true,
+    },
+    HotkeyRow {
+        keys: "Esc",
+        description: "Pause / resume; close the top dialog",
+        essential: true,
+    },
+    HotkeyRow {
+        keys: "F1",
+        description: "Help / controls",
+        essential: true,
+    },
+    HotkeyRow {
+        keys: "S",
+        description: "Stats & progression",
+        essential: true,
+    },
+    HotkeyRow {
+        keys: "A",
+        description: "Achievements",
+        essential: true,
+    },
+    HotkeyRow {
+        keys: "O",
+        description: "Settings",
+        essential: true,
+    },
+    HotkeyRow {
+        keys: "P",
+        description: "Profile",
+        essential: false,
+    },
+    HotkeyRow {
+        keys: "L",
+        description: "Leaderboard",
+        essential: false,
+    },
+    HotkeyRow {
+        keys: "C",
+        description: "Daily Challenge",
+        essential: false,
+    },
+    HotkeyRow {
+        keys: "Z",
+        description: "Zen mode",
+        essential: false,
+    },
+    HotkeyRow {
+        keys: "X",
+        description: "Challenge mode",
+        essential: false,
+    },
+    HotkeyRow {
+        keys: "T",
+        description: "Time Attack",
+        essential: false,
+    },
+    HotkeyRow {
+        keys: "G",
+        description: "Give up the current deal",
+        essential: false,
+    },
+    HotkeyRow {
+        keys: "[ / ]",
+        description: "Volume down / up",
+        essential: false,
+    },
+    HotkeyRow {
+        keys: "F11",
+        description: "Toggle fullscreen",
+        essential: false,
+    },
+    HotkeyRow {
+        keys: "/ (hold)",
+        description: "This cheat sheet",
+        essential: false,
+    },
+];
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn table_is_populated_and_well_formed() {
+        assert!(!HOTKEYS.is_empty());
+        for row in HOTKEYS {
+            assert!(!row.keys.trim().is_empty(), "empty keys cell");
+            assert!(
+                !row.description.trim().is_empty(),
+                "empty description for {}",
+                row.keys
+            );
+        }
+    }
+
+    #[test]
+    fn essential_subset_is_a_teachable_size() {
+        let essentials = HOTKEYS.iter().filter(|r| r.essential).count();
+        assert!(
+            (6..=12).contains(&essentials),
+            "the onboarding slide wants a skimmable essential set, got {essentials}"
+        );
+    }
+
+    #[test]
+    fn keys_cells_are_unique() {
+        let mut seen = std::collections::HashSet::new();
+        for row in HOTKEYS {
+            assert!(seen.insert(row.keys), "duplicate hotkey row: {}", row.keys);
+        }
+    }
+}

solitaire_engine/src/hud_plugin/fx.rs

@@ -109,12 +109,19 @@ pub(super) fn apply_action_fade(
 /// Visual feedback for every action button — paints idle / hover / pressed
 /// states by mutating `BackgroundColor` whenever the interaction state
 /// changes. One query covers all action buttons via the shared
-/// `ActionButton` marker.
+/// `ActionButton` marker. Glass tab-bar buttons are excluded: they carry
+/// their own per-button colour triple and are painted by
+/// `paint_glass_tab_buttons` instead (this system's opaque `ACTION_BTN_*`
+/// fills would destroy the translucent glass look).
 #[allow(clippy::type_complexity)]
 pub(super) fn paint_action_buttons(
     mut buttons: Query<
         (&Interaction, &mut BackgroundColor),
-        (With<ActionButton>, Changed<Interaction>),
+        (
+            With<ActionButton>,
+            Without<GlassTabButton>,
+            Changed<Interaction>,
+        ),
     >,
 ) {
     for (interaction, mut bg) in &mut buttons {

solitaire_engine/src/hud_plugin/mod.rs

@@ -12,11 +12,13 @@ use bevy::window::WindowResized;
 mod fx;
 mod interaction;
 mod spawn;
+pub(crate) mod tab_bar;
 mod updates;
 
 pub use fx::*;
 use interaction::*;
 use spawn::*;
+use tab_bar::*;
 use updates::*;
 
 // On wasm32 AvatarPlugin is gated out; define a placeholder type so the
@@ -595,6 +597,13 @@ impl Plugin for HudPlugin {
                     handle_menu_backdrop_click,
                     close_menu_popover_on_escape,
                     paint_action_buttons,
+                    paint_glass_tab_buttons,
+                    drive_tab_expansion,
+                    // Writes tab-label TextColor and reads TextFont — entity-
+                    // disjoint from the UiTextFx readout writers (tab labels
+                    // vs HUD readouts), which Bevy can't prove, so declare it.
+                    animate_tab_expansion.ambiguous_with(UiTextFx),
+                    duck_tab_bar_during_drag,
                 )
                     .chain()
                     .in_set(HudButtons)

solitaire_engine/src/hud_plugin/spawn.rs

@@ -360,6 +360,7 @@ pub(super) fn handle_avatar_button(
 pub(super) fn spawn_action_buttons(
     font_res: Option<Res<FontResource>>,
     windows: Query<&Window>,
+    images: Option<ResMut<Assets<Image>>>,
     mut commands: Commands,
 ) {
     let action_font_size =
@@ -370,9 +371,18 @@ pub(super) fn spawn_action_buttons(
         ..default()
     };
 
-    // Bottom bar: full-width, centered, sits above the gesture-navigation zone.
+    // Touch layout: the floating glass tab bar (pill + circular Menu).
+    // `Assets<Image>` is absent under `MinimalPlugins`; `rasterize_into`
+    // returning `None` switches the bar to its text-fallback form.
+    if USE_TOUCH_UI_LAYOUT {
+        let icons = images.and_then(|mut imgs| TabIcons::rasterize_into(&mut imgs));
+        spawn_glass_tab_bar(&mut commands, &font, icons.as_ref());
+        return;
+    }
+
+    // Desktop bottom bar: full-width, centered, docked to the bottom edge.
     // `SafeAreaAnchoredBottom` applies the correct logical-pixel inset once
-    // Android reports it (frames 1-3); initial value is 0.0.
+    // the platform reports it; initial value is 0.0.
     commands
         .spawn((
             Node {
@@ -400,73 +410,10 @@ pub(super) fn spawn_action_buttons(
             HudActionBar,
         ))
         .with_children(|row| {
-            if USE_TOUCH_UI_LAYOUT {
-                spawn_touch_action_bar(row, &font);
-            } else {
-                spawn_desktop_action_bar(row, &font);
-            }
+            spawn_desktop_action_bar(row, &font);
         });
 }
 
-/// Phase F touch action bar — five buttons, three of them big.
-///
-/// The core gameplay trio (**Undo · Draw · Hint**) gets enlarged
-/// thumb-reach targets; Menu and Pause stay compact at the edges. The
-/// utility actions the desktop bar carries are reachable elsewhere on
-/// touch and are deliberately absent here: Help lives in Menu → System,
-/// mode switching lives on the Home screen (Phase B), and New Game is
-/// Home's hero button. Draw duplicates the stock-pile tap so the most
-/// frequent action of all no longer requires reaching the top half of a
-/// tall folded screen.
-pub(super) fn spawn_touch_action_bar(row: &mut ChildSpawnerCommands, font: &TextFont) {
-    // The trailing `order` argument feeds `Focusable { group: Hud, order }`
-    // so Tab (external keyboard) cycles the bar in visual reading order.
-    spawn_action_button(
-        row,
-        MenuButton,
-        "Menu",
-        None,
-        "Open Home, Stats, Achievements, Profile, Settings, or Leaderboard.",
-        font,
-        0,
-        TEXT_SECONDARY,
-    );
-    spawn_primary_action_button(
-        row,
-        UndoButton,
-        "Undo",
-        "Take back your last move. Hold to keep undoing. Costs points and blocks No Undo.",
-        font,
-        1,
-    );
-    spawn_primary_action_button(
-        row,
-        DrawButton,
-        "Draw",
-        "Draw from the stock — same as tapping the deck.",
-        font,
-        2,
-    );
-    spawn_primary_action_button(
-        row,
-        HintButton,
-        TOUCH_HINT_LABEL,
-        "Highlight a suggested move. Cycles through alternatives on repeat taps.",
-        font,
-        3,
-    );
-    spawn_action_button(
-        row,
-        PauseButton,
-        "Pause",
-        None,
-        "Pause the game and freeze the timer.",
-        font,
-        4,
-        TEXT_SECONDARY,
-    );
-}
-
 /// Desktop action bar — unchanged by Phase F (decision 5: the touch bar
 /// is touch-only). All seven actions, uniform sizing.
 pub(super) fn spawn_desktop_action_bar(row: &mut ChildSpawnerCommands, font: &TextFont) {
@@ -585,44 +532,9 @@ pub(super) fn spawn_action_button<M: Component>(
     );
 }
 
-/// Enlarged variant for the touch bar's core gameplay trio (Phase F):
-/// bigger padding / minimum target and a scaled-up label so Undo, Draw,
-/// and Hint read (and hit) as the primary actions. Hotkey chips are
-/// irrelevant on touch, so the variant takes none.
-pub(super) fn spawn_primary_action_button<M: Component>(
-    row: &mut ChildSpawnerCommands,
-    marker: M,
-    label: &str,
-    tooltip: &'static str,
-    font: &TextFont,
-    order: i32,
-) {
-    let (pad, min_w, min_h) = primary_action_button_metrics();
-    let primary_font = TextFont {
-        font: font.font.clone(),
-        // 1.35× the bar's responsive size, capped so landscape tablets
-        // don't blow the row height out.
-        font_size: (font.font_size * 1.35).min(24.0),
-        ..default()
-    };
-    spawn_action_button_sized(
-        row,
-        marker,
-        label,
-        None,
-        tooltip,
-        &primary_font,
-        order,
-        TEXT_PRIMARY,
-        pad,
-        min_w,
-        min_h,
-    );
-}
-
-/// Shared body of [`spawn_action_button`] / [`spawn_primary_action_button`]
-/// — one place owns the component set so `paint_action_buttons`, tooltips,
-/// and the focus ring treat every bar button identically.
+/// Shared body of [`spawn_action_button`] — one place owns the component
+/// set so `paint_action_buttons`, tooltips, and the focus ring treat every
+/// bar button identically.
 #[allow(clippy::too_many_arguments)]
 fn spawn_action_button_sized<M: Component>(
     row: &mut ChildSpawnerCommands,

solitaire_engine/src/hud_plugin/tab_bar.rs

@@ -0,0 +1,529 @@
+//! Floating "liquid glass" touch tab bar — layout and animation.
+//!
+//! Replaces the docked full-width touch action bar (Phase F) with an
+//! iOS-26-style floating arrangement: a pill of icon buttons hovering
+//! above the bottom edge, plus a detached circular Menu button to its
+//! right. The *visual treatment* (translucent sheen, specular rim, drop
+//! shadow) lives in [`crate::ui_glass`]; this module owns only geometry,
+//! button wiring, and the expand/collapse label animation, so the glass
+//! material can be swapped without touching layout.
+//!
+//! Interaction compatibility: every button keeps the same marker
+//! components as the old bar (`UndoButton`, `DrawButton`, …) plus
+//! `ActionButton`, `Button`, `Tooltip`, and `Focusable`, so the click
+//! handlers, tooltips, focus ring, and the tap-to-toggle chrome guard in
+//! `interaction.rs` all work unchanged.
+//!
+//! Expansion model (user decision, 2026-07-15): **Draw** — the most
+//! frequent action — is the persistently-expanded "active" pill showing
+//! icon + label; the other buttons are icon-only and reveal their label
+//! with a width-animated slide while pressed.
+
+use super::*;
+use crate::assets::hud_icon_svg::HudIcon;
+use crate::ui_glass::{GLASS_BORDER_PX, glass_surface};
+use crate::ui_theme::{ACCENT_PRIMARY_HOVER, SPACE_3};
+use bevy::text::{LineBreak, TextLayout};
+use bevy::ui::{Overflow, UiTransform, Val2};
+
+use crate::resources::DragState;
+use crate::safe_area::SafeAreaInsets;
+
+/// Height of both the pill and the circular Menu button, in logical px.
+/// 64 keeps the inner 48-px buttons comfortably past the 44-px touch
+/// floor with 8 px of glass around them.
+pub(crate) const TAB_BAR_HEIGHT: f32 = 64.0;
+
+/// Gap between the bar and the bottom screen edge (the "floating" margin;
+/// the Android gesture-bar inset is added on top by `SafeAreaAnchoredBottom`).
+const TAB_BAR_MARGIN: f32 = SPACE_3;
+
+/// Vertical space UI stacked above the bar (the toast stack) must clear:
+/// floating margin + bar height + one spacing step of breathing room.
+pub(crate) const TAB_BAR_CLEARANCE_PX: f32 = TAB_BAR_MARGIN + TAB_BAR_HEIGHT + SPACE_2;
+
+/// Diameter of a button inside the pill (and its fully-round radius ×2).
+const TAB_BUTTON_SIZE: f32 = 48.0;
+
+/// Displayed icon size in logical px (texture is rasterised larger; see
+/// `assets::hud_icon_svg::HUD_ICON_TEXTURE_PX`).
+const TAB_ICON_PX: f32 = 24.0;
+
+/// FiraMono glyph advance as a fraction of font size. The bar is
+/// monospace-only, so `chars × advance × font_size` is the exact label
+/// width — the same ratio `action_bar_font_size` documents.
+const FIRA_ADVANCE: f32 = 0.62;
+
+/// Gap between an icon and its revealed label, folded into the animated
+/// wrapper width so it collapses together with the text.
+const LABEL_LEAD_PX: f32 = SPACE_2;
+
+/// Idle fill of an inactive icon button — fully transparent so the pill's
+/// glass shows through untouched.
+const GLASS_BTN_IDLE: Color = Color::srgba(1.0, 1.0, 1.0, 0.0);
+/// Hover fill of an inactive icon button (desktop pointer / DPAD focus).
+const GLASS_BTN_HOVER: Color = Color::srgba(1.0, 1.0, 1.0, 0.08);
+/// Pressed fill of an inactive icon button.
+const GLASS_BTN_PRESSED: Color = Color::srgba(1.0, 1.0, 1.0, 0.14);
+/// Pressed state of the active (accent-filled) pill — darker than idle so
+/// the press reads as the surface receding, mirroring `BG_ELEVATED_PRESSED`.
+const GLASS_ACTIVE_PRESSED: Color = Color::srgb(0.55, 0.22, 0.22);
+
+/// Idle / hovered / pressed fills for one tab-bar button. Presence of this
+/// component also routes the button to `paint_glass_tab_buttons` instead of
+/// the legacy `paint_action_buttons` (which excludes it).
+#[derive(Component, Debug)]
+pub struct GlassTabButton {
+    idle: Color,
+    hovered: Color,
+    pressed: Color,
+}
+
+/// Animated label-reveal state, on the clipping wrapper node between the
+/// button and its `Text` label. `progress` ∈ [0, 1] maps to wrapper width
+/// via [`expansion_width`]; `target` is where it is heading.
+#[derive(Component, Debug)]
+pub struct TabLabelWrap {
+    /// Current reveal amount, 0 = collapsed, 1 = fully expanded.
+    pub progress: f32,
+    /// Reveal amount the animation is moving towards.
+    pub target: f32,
+    /// `true` keeps the label expanded regardless of interaction —
+    /// the persistent Draw pill, and every button in text-fallback mode.
+    persistent: bool,
+    /// Label length; width is recomputed from the live font size each
+    /// frame so viewport-driven font rescales stay correct.
+    label_chars: usize,
+    /// Last width written to the node, to skip no-op layout writes.
+    last_width: f32,
+}
+
+/// Marker on the label `Text` inside a [`TabLabelWrap`].
+#[derive(Component, Debug)]
+pub struct TabLabel;
+
+/// Duck-away state on the bar container: while a card drag is committed
+/// the whole bar slides below the screen edge so it never occludes a
+/// drop target on the bottom tableau rows, then slides back on release.
+/// `progress` ∈ [0, 1]; 1 = fully off-screen.
+#[derive(Component, Debug)]
+pub struct TabBarDuck {
+    /// Current slide amount, animated by [`duck_tab_bar_during_drag`].
+    pub progress: f32,
+}
+
+/// Extra slide distance past the bar's own height so its drop shadow
+/// (16 px blur + 6 px offset) also clears the screen edge.
+const DUCK_SHADOW_ALLOWANCE_PX: f32 = 24.0;
+
+/// Rasterised icon textures for the five tab-bar actions.
+pub(super) struct TabIcons {
+    undo: Handle<Image>,
+    draw: Handle<Image>,
+    hint: Handle<Image>,
+    pause: Handle<Image>,
+    menu: Handle<Image>,
+}
+
+impl TabIcons {
+    /// Rasterise all five icons into `images`. Returns `None` (and warns)
+    /// if any icon fails — the caller then falls back to text-only labels,
+    /// so a bad SVG degrades the look, never the playability.
+    pub(super) fn rasterize_into(images: &mut Assets<Image>) -> Option<Self> {
+        let mut add = |icon: HudIcon| match icon.rasterize() {
+            Ok(img) => Some(images.add(img)),
+            Err(e) => {
+                warn!("tab_bar: failed to rasterise {icon:?} icon: {e}");
+                None
+            }
+        };
+        Some(Self {
+            undo: add(HudIcon::Undo)?,
+            draw: add(HudIcon::Draw)?,
+            hint: add(HudIcon::Hint)?,
+            pause: add(HudIcon::Pause)?,
+            menu: add(HudIcon::Menu)?,
+        })
+    }
+}
+
+/// Wrapper width in logical px for a label of `chars` monospace glyphs at
+/// `font_size`, revealed to `progress`. Pure so the animation curve is
+/// unit-testable without an app.
+pub(super) fn expansion_width(chars: usize, font_size: f32, progress: f32) -> f32 {
+    progress.clamp(0.0, 1.0) * (LABEL_LEAD_PX + chars as f32 * font_size * FIRA_ADVANCE)
+}
+
+/// Advance `progress` towards `target` by one frame of `dt` seconds.
+/// Linear tween over `MOTION_SLIDE_SECS`, snapping when reduce-motion is
+/// active. Pure for the same reason as [`expansion_width`].
+pub(super) fn step_expansion(progress: f32, target: f32, dt: f32, reduce_motion: bool) -> f32 {
+    if reduce_motion {
+        return target;
+    }
+    let max_step = dt / crate::ui_theme::MOTION_SLIDE_SECS;
+    progress + (target - progress).clamp(-max_step, max_step)
+}
+
+/// Spawns the floating glass tab bar: one full-width invisible flex row
+/// (carrying the `HudActionBar` marker so chrome show/hide keeps working)
+/// centring the glass pill and the detached circular Menu button.
+///
+/// `icons: None` (rasteriser unavailable, e.g. `MinimalPlugins` tests, or
+/// an SVG regression) switches every button to text-fallback: labels stay
+/// expanded so the bar remains fully usable without textures.
+pub(super) fn spawn_glass_tab_bar(
+    commands: &mut Commands,
+    font: &TextFont,
+    icons: Option<&TabIcons>,
+) {
+    let text_fallback = icons.is_none();
+    commands
+        .spawn((
+            Node {
+                position_type: PositionType::Absolute,
+                bottom: Val::Px(TAB_BAR_MARGIN),
+                left: Val::Px(0.0),
+                width: Val::Percent(100.0),
+                flex_direction: FlexDirection::Row,
+                justify_content: JustifyContent::Center,
+                align_items: AlignItems::Center,
+                column_gap: VAL_SPACE_3,
+                ..default()
+            },
+            ZIndex(Z_HUD),
+            SafeAreaAnchoredBottom {
+                base_bottom: TAB_BAR_MARGIN,
+            },
+            HudActionBar,
+            TabBarDuck { progress: 0.0 },
+            UiTransform::IDENTITY,
+        ))
+        .with_children(|bar| {
+            // The main pill: Undo · [Draw] · Hint · Pause.
+            bar.spawn((
+                Node {
+                    height: Val::Px(TAB_BAR_HEIGHT),
+                    flex_direction: FlexDirection::Row,
+                    align_items: AlignItems::Center,
+                    padding: UiRect::axes(Val::Px(SPACE_2), Val::Px(0.0)),
+                    column_gap: Val::Px(4.0),
+                    border: UiRect::all(Val::Px(GLASS_BORDER_PX)),
+                    border_radius: BorderRadius::all(Val::Px(TAB_BAR_HEIGHT / 2.0)),
+                    ..default()
+                },
+                glass_surface(),
+            ))
+            .with_children(|pill| {
+                spawn_tab_button(
+                    pill,
+                    UndoButton,
+                    "Undo",
+                    "Take back your last move. Hold to keep undoing. Costs points and blocks No Undo.",
+                    font,
+                    0,
+                    icons.map(|i| i.undo.clone()),
+                    false,
+                    text_fallback,
+                );
+                spawn_tab_button(
+                    pill,
+                    DrawButton,
+                    "Draw",
+                    "Draw from the stock — same as tapping the deck.",
+                    font,
+                    1,
+                    icons.map(|i| i.draw.clone()),
+                    true,
+                    text_fallback,
+                );
+                spawn_tab_button(
+                    pill,
+                    HintButton,
+                    TOUCH_HINT_LABEL,
+                    "Highlight a suggested move. Cycles through alternatives on repeat taps.",
+                    font,
+                    2,
+                    icons.map(|i| i.hint.clone()),
+                    false,
+                    text_fallback,
+                );
+                spawn_tab_button(
+                    pill,
+                    PauseButton,
+                    "Pause",
+                    "Pause the game and freeze the timer.",
+                    font,
+                    3,
+                    icons.map(|i| i.pause.clone()),
+                    false,
+                    text_fallback,
+                );
+            });
+
+            // The detached circular Menu button, same glass material.
+            bar.spawn((
+                MenuButton,
+                ActionButton,
+                Button,
+                GlassTabButton {
+                    idle: GLASS_BTN_IDLE,
+                    hovered: GLASS_BTN_HOVER,
+                    pressed: GLASS_BTN_PRESSED,
+                },
+                Tooltip::new(
+                    "Open Home, Stats, Achievements, Profile, Settings, or Leaderboard.",
+                ),
+                Focusable {
+                    group: FocusGroup::Hud,
+                    order: 4,
+                },
+                Node {
+                    width: Val::Px(TAB_BAR_HEIGHT),
+                    height: Val::Px(TAB_BAR_HEIGHT),
+                    justify_content: JustifyContent::Center,
+                    align_items: AlignItems::Center,
+                    border: UiRect::all(Val::Px(GLASS_BORDER_PX)),
+                    border_radius: BorderRadius::all(Val::Px(TAB_BAR_HEIGHT / 2.0)),
+                    ..default()
+                },
+                BackgroundColor(GLASS_BTN_IDLE),
+                glass_surface(),
+            ))
+            .with_children(|circle| {
+                if let Some(icons) = icons {
+                    spawn_tab_icon(circle, icons.menu.clone(), TEXT_PRIMARY);
+                } else {
+                    // Text fallback: a menu glyph-free label keeps the
+                    // button discoverable without any texture.
+                    circle.spawn((
+                        Text::new("Menu"),
+                        TextLayout::new_with_linebreak(LineBreak::NoWrap),
+                        font.clone(),
+                        TextColor(TEXT_PRIMARY),
+                    ));
+                }
+            });
+        });
+}
+
+/// Spawns one button inside the pill: icon, then the width-animated label
+/// wrapper. `active` gives the accent-filled persistent pill (Draw);
+/// `text_fallback` pins every label open when icons are unavailable.
+#[allow(clippy::too_many_arguments)]
+fn spawn_tab_button<M: Component>(
+    pill: &mut ChildSpawnerCommands,
+    marker: M,
+    label: &str,
+    tooltip: &'static str,
+    font: &TextFont,
+    order: i32,
+    icon: Option<Handle<Image>>,
+    active: bool,
+    text_fallback: bool,
+) {
+    let (idle, hovered, pressed) = if active {
+        (ACCENT_PRIMARY, ACCENT_PRIMARY_HOVER, GLASS_ACTIVE_PRESSED)
+    } else {
+        (GLASS_BTN_IDLE, GLASS_BTN_HOVER, GLASS_BTN_PRESSED)
+    };
+    let icon_tint = if active { TEXT_PRIMARY } else { TEXT_SECONDARY };
+    let persistent = active || text_fallback;
+    let start = if persistent { 1.0 } else { 0.0 };
+    let chars = label.chars().count();
+
+    pill.spawn((
+        marker,
+        ActionButton,
+        Button,
+        GlassTabButton {
+            idle,
+            hovered,
+            pressed,
+        },
+        Tooltip::new(tooltip),
+        Focusable {
+            group: FocusGroup::Hud,
+            order,
+        },
+        Node {
+            height: Val::Px(TAB_BUTTON_SIZE),
+            min_width: Val::Px(TAB_BUTTON_SIZE),
+            flex_direction: FlexDirection::Row,
+            justify_content: JustifyContent::Center,
+            align_items: AlignItems::Center,
+            padding: UiRect::axes(Val::Px(SPACE_3), Val::Px(0.0)),
+            border_radius: BorderRadius::all(Val::Px(TAB_BUTTON_SIZE / 2.0)),
+            ..default()
+        },
+        BackgroundColor(idle),
+    ))
+    .with_children(|b| {
+        if let Some(handle) = icon {
+            spawn_tab_icon(b, handle, icon_tint);
+        }
+        // The clipping wrapper the animation drives. Label text sits
+        // left-anchored inside, so growing the width reveals it
+        // left-to-right and shrinking clips it from the right.
+        b.spawn((
+            TabLabelWrap {
+                progress: start,
+                target: start,
+                persistent,
+                label_chars: chars,
+                last_width: f32::NAN,
+            },
+            Node {
+                overflow: Overflow::clip(),
+                width: Val::Px(expansion_width(chars, font.font_size, start)),
+                height: Val::Percent(100.0),
+                align_items: AlignItems::Center,
+                justify_content: JustifyContent::FlexEnd,
+                ..default()
+            },
+        ))
+        .with_children(|wrap| {
+            let mut color = TEXT_PRIMARY;
+            color.set_alpha(start);
+            wrap.spawn((
+                TabLabel,
+                ActionButtonLabel,
+                Text::new(label),
+                TextLayout::new_with_linebreak(LineBreak::NoWrap),
+                font.clone(),
+                TextColor(color),
+            ));
+        });
+    });
+}
+
+/// One fixed-size tinted icon node.
+fn spawn_tab_icon(parent: &mut ChildSpawnerCommands, handle: Handle<Image>, tint: Color) {
+    parent.spawn((
+        ImageNode {
+            color: tint,
+            ..ImageNode::new(handle)
+        },
+        Node {
+            width: Val::Px(TAB_ICON_PX),
+            height: Val::Px(TAB_ICON_PX),
+            flex_shrink: 0.0,
+            ..default()
+        },
+    ));
+}
+
+/// Sets each label wrapper's animation target from its button's
+/// interaction state: persistent wrappers pin to 1, the rest expand while
+/// pressed or hovered and collapse on release.
+pub(super) fn drive_tab_expansion(
+    buttons: Query<(&Interaction, &Children), With<GlassTabButton>>,
+    mut wraps: Query<&mut TabLabelWrap>,
+) {
+    for (interaction, children) in &buttons {
+        for child in children.iter() {
+            let Ok(mut wrap) = wraps.get_mut(child) else {
+                continue;
+            };
+            let target = if wrap.persistent || !matches!(interaction, Interaction::None) {
+                1.0
+            } else {
+                0.0
+            };
+            // Bypass change detection on no-ops so `animate_tab_expansion`
+            // and layout stay idle while nothing moves.
+            if wrap.target != target {
+                wrap.target = target;
+            }
+        }
+    }
+}
+
+/// Advances every label reveal towards its target and writes the wrapper
+/// width + label alpha. Width is derived from the label's *live* font size,
+/// so the Fold's posture-change font rescale re-widens expanded labels
+/// automatically. Node writes are skipped when the width is unchanged to
+/// avoid dirtying UI layout every frame.
+pub(super) fn animate_tab_expansion(
+    time: Res<Time>,
+    settings: Option<Res<SettingsResource>>,
+    mut wraps: Query<(&mut TabLabelWrap, &mut Node, &Children)>,
+    mut labels: Query<(&TextFont, &mut TextColor), With<TabLabel>>,
+) {
+    let reduce_motion = settings.as_deref().is_some_and(|s| s.0.reduce_motion_mode);
+    let dt = time.delta_secs();
+    for (mut wrap, mut node, children) in &mut wraps {
+        for child in children.iter() {
+            let Ok((font, mut text_color)) = labels.get_mut(child) else {
+                continue;
+            };
+            let next = step_expansion(wrap.progress, wrap.target, dt, reduce_motion);
+            let width = expansion_width(wrap.label_chars, font.font_size, next);
+            // `!=` (not epsilon) is deliberate: last_width starts NaN so the
+            // first frame always writes, and equal floats mean a true no-op.
+            if next != wrap.progress || width != wrap.last_width {
+                wrap.progress = next;
+                wrap.last_width = width;
+                node.width = Val::Px(width);
+                text_color.0.set_alpha(next);
+            }
+            break;
+        }
+    }
+}
+
+/// Slides the bar off the bottom edge while a card drag is committed and
+/// back once it ends. Effectively touch-only: the desktop docked bar
+/// never carries [`TabBarDuck`], so the query is empty there.
+///
+/// The slide animates `UiTransform::translation` (a render-time offset,
+/// +y = down) rather than `Node::bottom`, for two reasons: layout is
+/// never dirtied mid-drag (the whole point is not to cost frames while
+/// the player is dragging), and `Node::bottom` is owned by the safe-area
+/// anchor system — two writers on one field would fight.
+pub(super) fn duck_tab_bar_during_drag(
+    time: Res<Time>,
+    settings: Option<Res<SettingsResource>>,
+    drag: Option<Res<DragState>>,
+    insets: Option<Res<SafeAreaInsets>>,
+    windows: Query<&Window>,
+    mut bars: Query<(&mut TabBarDuck, &mut UiTransform), With<HudActionBar>>,
+) {
+    let target = if drag.as_deref().is_some_and(|d| d.committed) {
+        1.0
+    } else {
+        0.0
+    };
+    let reduce_motion = settings.as_deref().is_some_and(|s| s.0.reduce_motion_mode);
+    let dt = time.delta_secs();
+    // Physical-px inset → logical, same conversion the safe-area anchors
+    // apply (CLAUDE.md §10): the bar sits `inset` above its base position,
+    // so the slide must cover that extra travel to fully clear the edge.
+    let scale = windows.iter().next().map_or(1.0, |w| w.scale_factor());
+    let inset_logical = insets.as_deref().map_or(0.0, |i| i.bottom / scale);
+    let slide_px = TAB_BAR_CLEARANCE_PX + inset_logical + DUCK_SHADOW_ALLOWANCE_PX;
+    for (mut duck, mut transform) in &mut bars {
+        let next = step_expansion(duck.progress, target, dt, reduce_motion);
+        if next == duck.progress && duck.progress == target {
+            continue;
+        }
+        duck.progress = next;
+        transform.translation = Val2::px(0.0, next * slide_px);
+    }
+}
+
+/// Idle / hover / pressed feedback for glass tab buttons — the glass
+/// counterpart of `paint_action_buttons`, using each button's own colour
+/// triple so the accent-filled active pill and the transparent icon
+/// buttons share one system.
+pub(super) fn paint_glass_tab_buttons(
+    mut buttons: Query<(&Interaction, &GlassTabButton, &mut BackgroundColor), Changed<Interaction>>,
+) {
+    for (interaction, style, mut bg) in &mut buttons {
+        bg.0 = match interaction {
+            Interaction::Pressed => style.pressed,
+            Interaction::Hovered => style.hovered,
+            Interaction::None => style.idle,
+        };
+    }
+}

solitaire_engine/src/hud_plugin/tests.rs

@@ -907,6 +907,10 @@ fn hud_focus_only_engages_when_button_hovered() {
 /// Bare app (no `HudPlugin`) so bar-content assertions count only the
 /// buttons the tested spawn function creates — `headless_app` would
 /// pre-spawn the platform-default bar and pollute the counts.
+///
+/// The touch branch spawns the glass tab bar with `icons: None`
+/// (`MinimalPlugins` has no `Assets<Image>`), which exercises the
+/// text-fallback path — same markers, labels pinned expanded.
 fn bar_only_app(touch: bool) -> App {
     let mut app = App::new();
     app.add_plugins(MinimalPlugins);
@@ -914,13 +918,13 @@ fn bar_only_app(touch: bool) -> App {
     let font = TextFont::default();
     let world = app.world_mut();
     let mut commands = world.commands();
-    commands.spawn(Node::default()).with_children(|row| {
-        if touch {
-            spawn_touch_action_bar(row, &font);
-        } else {
+    if touch {
+        spawn_glass_tab_bar(&mut commands, &font, None);
+    } else {
+        commands.spawn(Node::default()).with_children(|row| {
             spawn_desktop_action_bar(row, &font);
-        }
-    });
+        });
+    }
     app.update();
     app
 }
@@ -933,7 +937,7 @@ fn count_buttons<C: Component>(app: &mut App) -> usize {
 }
 
 #[test]
-fn touch_action_bar_has_thumb_trio_plus_menu_and_pause() {
+fn touch_tab_bar_has_thumb_trio_plus_menu_and_pause() {
     let mut app = bar_only_app(true);
 
     assert_eq!(count_buttons::<UndoButton>(&mut app), 1);
@@ -949,6 +953,130 @@ fn touch_action_bar_has_thumb_trio_plus_menu_and_pause() {
     assert_eq!(count_buttons::<NewGameButton>(&mut app), 0);
 }
 
+/// The glass bar floats: its container must carry a bottom margin (not be
+/// docked at 0) both before and after safe-area insets arrive.
+#[test]
+fn glass_tab_bar_floats_above_bottom_edge() {
+    let mut app = bar_only_app(true);
+    let world = app.world_mut();
+    let mut q = world.query_filtered::<(&Node, &SafeAreaAnchoredBottom), With<HudActionBar>>();
+    let (node, anchor) = q.single(world).expect("glass bar container exists");
+    assert!(anchor.base_bottom > 0.0, "bar must float, not dock");
+    assert_eq!(node.bottom, Val::Px(anchor.base_bottom));
+}
+
+/// Draw is the persistently-expanded active pill (user decision
+/// 2026-07-15); with `icons: None` every wrapper is pinned expanded via
+/// text fallback, so instead assert on the *persistent* flag's effect:
+/// all wrappers spawn at full reveal and target full reveal.
+#[test]
+fn glass_tab_bar_text_fallback_pins_labels_expanded() {
+    let mut app = bar_only_app(true);
+    let world = app.world_mut();
+    let mut q = world.query::<&TabLabelWrap>();
+    let wraps: Vec<_> = q.iter(world).collect();
+    assert_eq!(wraps.len(), 4, "Undo/Draw/Hint/Pause each carry a wrapper");
+    for wrap in wraps {
+        assert_eq!(wrap.progress, 1.0);
+        assert_eq!(wrap.target, 1.0);
+    }
+}
+
+/// Focus order must match visual reading order: pill buttons left to
+/// right, then the detached Menu circle.
+#[test]
+fn glass_tab_bar_focus_order_reads_left_to_right() {
+    let mut app = bar_only_app(true);
+
+    for (f, expected) in [
+        (focusable_for::<UndoButton>(&mut app), 0),
+        (focusable_for::<DrawButton>(&mut app), 1),
+        (focusable_for::<HintButton>(&mut app), 2),
+        (focusable_for::<PauseButton>(&mut app), 3),
+        (focusable_for::<MenuButton>(&mut app), 4),
+    ] {
+        assert_eq!(f.group, FocusGroup::Hud);
+        assert_eq!(f.order, expected);
+    }
+}
+
+/// `expansion_width` is the single source of truth for the label reveal:
+/// zero when collapsed, lead + monospace advance when expanded, linear
+/// in between.
+#[test]
+fn expansion_width_is_linear_in_progress() {
+    assert_eq!(expansion_width(4, 16.0, 0.0), 0.0);
+    let full = expansion_width(4, 16.0, 1.0);
+    assert!(full > 4.0 * 16.0 * 0.62, "full width includes the lead gap");
+    let half = expansion_width(4, 16.0, 0.5);
+    assert!((half - full / 2.0).abs() < f32::EPSILON * 100.0);
+    // Out-of-range progress clamps rather than extrapolating.
+    assert_eq!(expansion_width(4, 16.0, 1.5), full);
+}
+
+/// While a committed drag is active the bar must slide down (positive
+/// `UiTransform` y — off-screen) and return to identity once the drag
+/// ends. Manual time steps make the tween deterministic.
+#[test]
+fn tab_bar_ducks_during_committed_drag_and_returns() {
+    use crate::resources::DragState;
+    use bevy::ui::UiTransform;
+
+    let mut app = bar_only_app(true);
+    set_manual_time_step(&mut app, 0.05);
+    app.add_systems(Update, duck_tab_bar_during_drag);
+    app.insert_resource(DragState {
+        committed: true,
+        ..default()
+    });
+
+    let translation_y_px = |app: &mut App| -> f32 {
+        let world = app.world_mut();
+        let mut q = world.query_filtered::<&UiTransform, With<HudActionBar>>();
+        let t = q.single(world).expect("bar carries UiTransform");
+        match t.translation.y {
+            Val::Px(px) => px,
+            other => panic!("duck must write Val::Px, got {other:?}"),
+        }
+    };
+
+    // 0.18s slide at 0.05s/frame: fully ducked within 5 frames.
+    app.update();
+    app.update();
+    let mid = translation_y_px(&mut app);
+    assert!(mid > 0.0, "bar must start sliding down: {mid}");
+    for _ in 0..5 {
+        app.update();
+    }
+    let ducked = translation_y_px(&mut app);
+    assert!(
+        ducked > TAB_BAR_CLEARANCE_PX,
+        "fully ducked bar must clear its own floating footprint: {ducked}"
+    );
+
+    // Drag ends → bar slides back to identity.
+    app.world_mut().resource_mut::<DragState>().committed = false;
+    for _ in 0..8 {
+        app.update();
+    }
+    assert_eq!(translation_y_px(&mut app), 0.0);
+}
+
+/// The tween must move at the `MOTION_SLIDE_SECS` rate, never overshoot,
+/// and snap instantly under reduce-motion.
+#[test]
+fn step_expansion_tweens_and_respects_reduce_motion() {
+    // One 60 fps frame covers 1/(0.18*60) ≈ 9.3% of the reveal.
+    let one_frame = step_expansion(0.0, 1.0, 1.0 / 60.0, false);
+    assert!(one_frame > 0.0 && one_frame < 0.2);
+    // A huge dt clamps at the target instead of overshooting.
+    assert_eq!(step_expansion(0.0, 1.0, 10.0, false), 1.0);
+    // Collapse works symmetrically.
+    assert!(step_expansion(1.0, 0.0, 1.0 / 60.0, false) < 1.0);
+    // Reduce-motion snaps regardless of dt.
+    assert_eq!(step_expansion(0.0, 1.0, 0.0, true), 1.0);
+}
+
 #[test]
 fn desktop_action_bar_keeps_all_seven_and_no_draw() {
     let mut app = bar_only_app(false);

solitaire_engine/src/hud_plugin/updates.rs

@@ -573,20 +573,6 @@ pub(super) fn action_button_metrics() -> (UiRect, Val, Val) {
     }
 }
 
-/// Metrics for the touch bar's enlarged Undo / Draw / Hint trio (Phase F).
-/// 96×64 px targets — comfortably past the 44 px accessibility floor and
-/// big enough to hit one-handed without looking. Only the touch layout
-/// spawns primary buttons, so no desktop branch is needed; the desktop
-/// values exist purely so host-side tests can exercise the touch spawn
-/// path with sensible numbers.
-pub(super) fn primary_action_button_metrics() -> (UiRect, Val, Val) {
-    (
-        UiRect::axes(Val::Px(10.0), Val::Px(8.0)),
-        Val::Px(96.0),
-        Val::Px(64.0),
-    )
-}
-
 pub(super) fn spawn_action_button_label(
     parent: &mut ChildSpawnerCommands,
     label: &str,

solitaire_engine/src/input_plugin/mod.rs

@@ -215,6 +215,7 @@ fn handle_keyboard_core(
     keys: Res<ButtonInput<KeyCode>>,
     paused: Option<Res<PausedResource>>,
     progress: Option<Res<ProgressResource>>,
+    drag: Res<DragState>,
     mut ev: CoreKeyboardMessages<'_>,
     mut time_attack: Option<ResMut<TimeAttackResource>>,
     selection: Option<Res<SelectionState>>,
@@ -227,6 +228,19 @@ fn handle_keyboard_core(
         return;
     }
 
+    // Mutual exclusion with pointer drags — mirrors `handle_selection_keys`.
+    // Undo / draw / new-game during an active mouse or touch drag would fire
+    // a StateChangedEvent whose card re-sync inserts a `CardAnim` on the
+    // dragged cards, fighting `follow_drag`'s per-frame Transform writes and
+    // leaving `DragState` origin indices stale against the mutated state.
+    // The keyboard-drag sentinel may proceed: `clear_selection_on_state_change`
+    // already drops that lift cleanly when the state moves.
+    if !drag.is_idle()
+        && drag.active_touch_id != Some(crate::selection_plugin::KEYBOARD_DRAG_TOUCH_ID)
+    {
+        return;
+    }
+
     // During replay playback (Playing or Completed) all game-input shortcuts
     // are suppressed. The replay overlay owns Space (pause/resume) and the
     // arrow keys (step). Letting game input through would mutate
@@ -473,11 +487,19 @@ pub fn emit_hint_visuals(
 fn handle_keyboard_forfeit(
     keys: Res<ButtonInput<KeyCode>>,
     paused: Option<Res<PausedResource>>,
+    drag: Res<DragState>,
     mut requests: MessageWriter<ForfeitRequestEvent>,
 ) {
     if paused.is_some_and(|p| p.0) {
         return;
     }
+    // Same pointer-drag exclusion as `handle_keyboard_core` — forfeiting
+    // mid-drag would mutate the game state under the dragged cards.
+    if !drag.is_idle()
+        && drag.active_touch_id != Some(crate::selection_plugin::KEYBOARD_DRAG_TOUCH_ID)
+    {
+        return;
+    }
     if !keys.just_pressed(KeyCode::KeyG) {
         return;
     }

solitaire_engine/src/input_plugin/tests.rs

@@ -817,3 +817,123 @@ fn pressing_h_spawns_pending_hint_task() {
         "pressing H must spawn an async hint task",
     );
 }
+
+// -----------------------------------------------------------------------
+// Pointer-drag / keyboard mutual exclusion.
+//
+// A state mutation fired while `follow_drag` is writing the dragged cards'
+// transforms every frame would make the card re-sync insert a `CardAnim`
+// on the same entities (two systems fighting over `Transform`) and leave
+// `DragState`'s origin indices stale. `handle_keyboard_core` and
+// `handle_keyboard_forfeit` therefore swallow game-mutating shortcuts
+// while a mouse or touch drag is live, mirroring `handle_selection_keys`.
+// The keyboard-lift sentinel is exempt: `clear_selection_on_state_change`
+// drops that lift cleanly when the state moves.
+// -----------------------------------------------------------------------
+
+fn keyboard_core_app() -> App {
+    let mut app = App::new();
+    app.add_plugins(MinimalPlugins);
+    app.add_message::<UndoRequestEvent>();
+    app.add_message::<NewGameRequestEvent>();
+    app.add_message::<InfoToastEvent>();
+    app.add_message::<DrawRequestEvent>();
+    app.add_message::<StartZenRequestEvent>();
+    app.init_resource::<ButtonInput<KeyCode>>();
+    app.init_resource::<DragState>();
+    app.add_systems(Update, handle_keyboard_core);
+    app
+}
+
+fn press_key(app: &mut App, key: KeyCode) {
+    let mut input = app.world_mut().resource_mut::<ButtonInput<KeyCode>>();
+    input.release(key);
+    input.clear();
+    input.press(key);
+}
+
+fn message_count<M: Message>(app: &App) -> usize {
+    let messages = app.world().resource::<Messages<M>>();
+    let mut cursor = messages.get_cursor();
+    cursor.read(messages).count()
+}
+
+fn set_drag(app: &mut App, active_touch_id: Option<u64>) {
+    let mut drag = app.world_mut().resource_mut::<DragState>();
+    drag.cards = vec![Card::new(Deck::Deck1, Suit::Clubs, Rank::Two)];
+    drag.committed = true;
+    drag.active_touch_id = active_touch_id;
+}
+
+#[test]
+fn u_key_fires_undo_when_no_drag_active() {
+    let mut app = keyboard_core_app();
+    press_key(&mut app, KeyCode::KeyU);
+    app.update();
+    assert_eq!(
+        message_count::<UndoRequestEvent>(&app),
+        1,
+        "U with an idle DragState must fire UndoRequestEvent",
+    );
+}
+
+#[test]
+fn u_key_ignored_during_committed_mouse_drag() {
+    let mut app = keyboard_core_app();
+    set_drag(&mut app, None); // mouse drag
+    press_key(&mut app, KeyCode::KeyU);
+    app.update();
+    assert_eq!(
+        message_count::<UndoRequestEvent>(&app),
+        0,
+        "U during a mouse drag must be swallowed",
+    );
+}
+
+#[test]
+fn draw_key_ignored_during_touch_drag() {
+    let mut app = keyboard_core_app();
+    set_drag(&mut app, Some(7)); // real touch id
+    press_key(&mut app, KeyCode::KeyD);
+    app.update();
+    assert_eq!(
+        message_count::<DrawRequestEvent>(&app),
+        0,
+        "D during a touch drag must be swallowed",
+    );
+}
+
+#[test]
+fn u_key_allowed_during_keyboard_lift() {
+    let mut app = keyboard_core_app();
+    set_drag(
+        &mut app,
+        Some(crate::selection_plugin::KEYBOARD_DRAG_TOUCH_ID),
+    );
+    press_key(&mut app, KeyCode::KeyU);
+    app.update();
+    assert_eq!(
+        message_count::<UndoRequestEvent>(&app),
+        1,
+        "the keyboard-lift sentinel must not block core shortcuts",
+    );
+}
+
+#[test]
+fn g_key_forfeit_ignored_during_mouse_drag() {
+    let mut app = App::new();
+    app.add_plugins(MinimalPlugins);
+    app.add_message::<ForfeitRequestEvent>();
+    app.init_resource::<ButtonInput<KeyCode>>();
+    app.init_resource::<DragState>();
+    app.add_systems(Update, handle_keyboard_forfeit);
+
+    set_drag(&mut app, None);
+    press_key(&mut app, KeyCode::KeyG);
+    app.update();
+    assert_eq!(
+        message_count::<ForfeitRequestEvent>(&app),
+        0,
+        "G during a mouse drag must be swallowed",
+    );
+}

solitaire_engine/src/leaderboard_plugin.rs

@@ -24,13 +24,13 @@ use crate::font_plugin::FontResource;
 use crate::settings_plugin::{SettingsResource, SettingsStoragePath};
 use crate::sync_plugin::SyncProviderResource;
 use crate::ui_modal::{
-    ButtonVariant, ModalScrim, ScrimDismissible, spawn_modal, spawn_modal_actions,
-    spawn_modal_button, spawn_modal_header,
+    ButtonVariant, ModalScrim, ScrimDismissible, spawn_empty_state, spawn_modal,
+    spawn_modal_actions, spawn_modal_button, spawn_modal_header,
 };
 use crate::ui_theme::{
-    ACCENT_PRIMARY, BG_ELEVATED, BORDER_SUBTLE, RADIUS_SM, STATE_INFO, TEXT_DISABLED, TEXT_PRIMARY,
-    TEXT_SECONDARY, TYPE_BODY, TYPE_BODY_LG, TYPE_CAPTION, VAL_SPACE_2, VAL_SPACE_3, VAL_SPACE_4,
-    Z_MODAL_PANEL, Z_PAUSE_DIALOG,
+    ACCENT_PRIMARY, BG_ELEVATED, BORDER_SUBTLE, RADIUS_SM, TEXT_DISABLED, TEXT_PRIMARY,
+    TEXT_SECONDARY, TYPE_BODY, TYPE_CAPTION, VAL_SPACE_2, VAL_SPACE_3, VAL_SPACE_4, Z_MODAL_PANEL,
+    Z_PAUSE_DIALOG,
 };
 
 // ---------------------------------------------------------------------------
@@ -536,11 +536,6 @@ fn spawn_leaderboard_screen(
             font_size: TYPE_CAPTION,
             ..default()
         };
-        let font_status = TextFont {
-            font: font_handle.clone(),
-            font_size: TYPE_BODY_LG,
-            ..default()
-        };
         let font_row = TextFont {
             font: font_handle.clone(),
             font_size: TYPE_BODY,
@@ -647,30 +642,31 @@ fn spawn_leaderboard_screen(
         .with_children(|body| {
             match data {
                 LeaderboardResource::Idle => {
-                    body.spawn((
-                        Text::new("Fetching\u{2026}"),
-                        font_status.clone(),
-                        TextColor(STATE_INFO),
-                    ));
+                    spawn_empty_state(
+                        body,
+                        "\u{21BB}",
+                        "Fetching the leaderboard\u{2026}",
+                        None,
+                        font_res,
+                    );
                 }
                 LeaderboardResource::Error(_) => {
-                    body.spawn((
-                        Text::new("Couldn't reach the leaderboard. Try again later."),
-                        font_status.clone(),
-                        TextColor(TEXT_SECONDARY),
-                    ));
+                    spawn_empty_state(
+                        body,
+                        "!",
+                        "Couldn't reach the leaderboard.",
+                        Some("Try again later."),
+                        font_res,
+                    );
                 }
                 LeaderboardResource::Loaded(rows) if rows.is_empty() => {
-                    body.spawn((
-                        Text::new("Be the first on the leaderboard."),
-                        font_status.clone(),
-                        TextColor(TEXT_PRIMARY),
-                    ));
-                    body.spawn((
-                        Text::new("Win a game and opt in to appear here."),
-                        font_row.clone(),
-                        TextColor(TEXT_SECONDARY),
-                    ));
+                    spawn_empty_state(
+                        body,
+                        "\u{2660}",
+                        "Be the first on the leaderboard.",
+                        Some("Win a game and opt in to appear here."),
+                        font_res,
+                    );
                 }
                 LeaderboardResource::Loaded(rows) => {
                     // Column headers

solitaire_engine/src/lib.rs

@@ -15,6 +15,8 @@ pub mod avatar_plugin;
 pub mod card_animation;
 pub mod card_plugin;
 pub mod challenge_plugin;
+pub mod cheat_sheet_plugin;
+pub mod contextual_tips_plugin;
 pub mod core_game_plugin;
 pub mod cursor_plugin;
 pub mod daily_challenge_plugin;
@@ -26,6 +28,7 @@ pub mod font_plugin;
 pub mod game_plugin;
 pub mod help_plugin;
 pub mod home_plugin;
+pub mod hotkeys;
 pub mod hud_plugin;
 pub mod input_plugin;
 pub mod layout;
@@ -60,6 +63,7 @@ pub mod theme_store_plugin;
 pub mod time_attack_plugin;
 pub mod touch_selection_plugin;
 pub mod ui_focus;
+pub mod ui_glass;
 pub mod ui_modal;
 pub mod ui_theme;
 pub mod ui_tooltip;
@@ -94,6 +98,8 @@ pub use card_plugin::{
 pub use challenge_plugin::{
     CHALLENGE_UNLOCK_LEVEL, ChallengeAdvancedEvent, ChallengePlugin, challenge_progress_label,
 };
+pub use cheat_sheet_plugin::{CheatSheetOverlay, CheatSheetPlugin};
+pub use contextual_tips_plugin::ContextualTipsPlugin;
 pub use core_game_plugin::CoreGamePlugin;
 pub use cursor_plugin::CursorPlugin;
 pub use daily_challenge_plugin::{

solitaire_engine/src/onboarding_plugin.rs

@@ -84,66 +84,11 @@ struct OnboardingSkipButton;
 pub struct OnboardingSlideIndex(pub u8);
 
 // ---------------------------------------------------------------------------
-// Slide data — hotkey rows are taken verbatim from `help_plugin.rs` so the
-// two screens stay in sync without a shared abstraction.
+// Slide data — the hotkey slide renders the essential subset of the
+// shared table in `crate::hotkeys` (Phase J unified the previously
+// diverging copies here and in help_plugin).
 // ---------------------------------------------------------------------------
 
-/// A single `key — description` pair shown on slide 3.
-#[cfg(not(target_os = "android"))]
-struct HotkeyRow {
-    keys: &'static str,
-    description: &'static str,
-}
-
-/// Most-used shortcuts from the `help_plugin` canonical list.
-///
-/// Updating the list in `help_plugin.rs` should be mirrored here. The
-/// ARCHITECTURE.md decision log calls out that we copy values rather than
-/// refactor the help plugin.
-#[cfg(not(target_os = "android"))]
-const HOTKEYS: &[HotkeyRow] = &[
-    HotkeyRow {
-        keys: "D / Space",
-        description: "Draw from stock",
-    },
-    HotkeyRow {
-        keys: "U",
-        description: "Undo last move",
-    },
-    HotkeyRow {
-        keys: "Tab → Enter",
-        description: "Pick a card; arrows pick where; Enter to drop",
-    },
-    HotkeyRow {
-        keys: "N",
-        description: "New Classic game",
-    },
-    HotkeyRow {
-        keys: "M",
-        description: "Open Mode Launcher (then 1–5 to pick)",
-    },
-    HotkeyRow {
-        keys: "S",
-        description: "Stats & progression",
-    },
-    HotkeyRow {
-        keys: "A",
-        description: "Achievements",
-    },
-    HotkeyRow {
-        keys: "O",
-        description: "Settings",
-    },
-    HotkeyRow {
-        keys: "Esc",
-        description: "Pause / resume",
-    },
-    HotkeyRow {
-        keys: "F1",
-        description: "Help / controls",
-    },
-];
-
 // ---------------------------------------------------------------------------
 // Plugin
 // ---------------------------------------------------------------------------
@@ -446,8 +391,10 @@ fn spawn_slide_hotkeys(commands: &mut Commands, font_res: Option<&FontResource>)
     spawn_modal(commands, OnboardingScreen, Z_ONBOARDING, |card| {
         spawn_modal_header(card, "Keyboard shortcuts", font_res);
 
-        // Vertical list of `key — description` rows, same chip style as HelpScreen.
-        for row in HOTKEYS {
+        // Vertical list of `key — description` rows, same chip style as
+        // HelpScreen. Essential subset only — the full table lives on
+        // the hold-`/` cheat sheet.
+        for row in crate::hotkeys::HOTKEYS.iter().filter(|r| r.essential) {
             card.spawn(Node {
                 flex_direction: FlexDirection::Row,
                 align_items: AlignItems::Center,
@@ -826,22 +773,15 @@ mod tests {
     }
 
     // -----------------------------------------------------------------------
-    // Hotkey list is non-empty (guards against accidental truncation)
+    // Hotkey slide renders a non-empty essential subset (the table's own
+    // integrity tests live in `crate::hotkeys`)
     // -----------------------------------------------------------------------
 
     #[test]
-    fn hotkey_list_is_non_empty() {
-        assert!(!HOTKEYS.is_empty(), "HOTKEYS must not be empty");
-    }
-
-    #[test]
-    fn all_hotkey_rows_have_non_empty_fields() {
-        for row in HOTKEYS {
-            assert!(!row.keys.is_empty(), "hotkey key field must not be empty");
-            assert!(
-                !row.description.is_empty(),
-                "hotkey description must not be empty"
-            );
-        }
+    fn hotkey_slide_subset_is_non_empty() {
+        assert!(
+            crate::hotkeys::HOTKEYS.iter().any(|r| r.essential),
+            "the onboarding slide needs at least one essential hotkey"
+        );
     }
 }

solitaire_engine/src/safe_area.rs

@@ -101,9 +101,10 @@ impl Plugin for SafeAreaInsetsPlugin {
 fn apply_safe_area_anchors(
     insets: Res<SafeAreaInsets>,
     windows: Query<&Window>,
+    ui_scale: Option<Res<UiScale>>,
     mut q: Query<(&SafeAreaAnchoredTop, &mut Node)>,
 ) {
-    if !insets.is_changed() {
+    if !insets.is_changed() && !ui_scale.as_ref().is_some_and(|s| s.is_changed()) {
         return;
     }
     // Android's WindowInsets API returns physical pixels; Bevy UI's Val::Px
@@ -119,19 +120,31 @@ fn apply_safe_area_anchors(
         );
     }
     let top_logical = raw_top.min(max_inset);
+    // `bevy::ui::UiScale` (Phase K) multiplies every Val::Px at layout
+    // time. `base_top` is UI chrome and SHOULD scale with the rest of
+    // the interface, but the system-bar inset is physical reality —
+    // pre-divide it so the post-multiplication offset stays exact.
+    let ui = effective_ui_scale(ui_scale.as_deref());
     for (anchor, mut node) in &mut q {
-        node.top = Val::Px(anchor.base_top + top_logical);
+        node.top = Val::Px(anchor.base_top + top_logical / ui);
     }
 }
 
+/// The live UI scale, defensively clamped — a zero or negative scale
+/// would flip or destroy the inset math.
+fn effective_ui_scale(ui_scale: Option<&UiScale>) -> f32 {
+    ui_scale.map_or(1.0, |s| s.0.max(0.1))
+}
+
 /// Re-applies `base_bottom + insets.bottom / scale` to every entity carrying
 /// [`SafeAreaAnchoredBottom`] whenever [`SafeAreaInsets`] changes.
 fn apply_safe_area_bottom_anchors(
     insets: Res<SafeAreaInsets>,
     windows: Query<&Window>,
+    ui_scale: Option<Res<UiScale>>,
     mut q: Query<(&SafeAreaAnchoredBottom, &mut Node)>,
 ) {
-    if !insets.is_changed() {
+    if !insets.is_changed() && !ui_scale.as_ref().is_some_and(|s| s.is_changed()) {
         return;
     }
     let scale = windows.iter().next().map_or(1.0, |w| w.scale_factor());
@@ -144,8 +157,12 @@ fn apply_safe_area_bottom_anchors(
         );
     }
     let bottom_logical = raw_bottom.min(max_inset);
+    // See `apply_safe_area_anchors`: the physical inset is pre-divided
+    // by the UI scale so a 90% setting can't sink the action bar into
+    // the gesture zone (and 130% doesn't over-inset it).
+    let ui = effective_ui_scale(ui_scale.as_deref());
     for (anchor, mut node) in &mut q {
-        node.bottom = Val::Px(anchor.base_bottom + bottom_logical);
+        node.bottom = Val::Px(anchor.base_bottom + bottom_logical / ui);
     }
 }
 
@@ -163,19 +180,23 @@ fn apply_safe_area_bottom_anchors(
 fn apply_safe_area_to_modal_scrims(
     insets: Res<SafeAreaInsets>,
     windows: Query<&Window>,
+    ui_scale: Option<Res<UiScale>>,
     mut scrims: Query<&mut Node, With<ModalScrim>>,
     new_scrims: Query<(), (With<ModalScrim>, Added<ModalScrim>)>,
 ) {
     let has_new = !new_scrims.is_empty();
-    if !insets.is_changed() && !has_new {
+    if !insets.is_changed() && !has_new && !ui_scale.as_ref().is_some_and(|s| s.is_changed()) {
         return;
     }
     let scale = windows.iter().next().map_or(1.0, |w| w.scale_factor());
     let window_height = windows.iter().next().map_or(800.0, |w| w.height());
     // Clamp each inset to 25% of screen height so an unexpectedly large OS
     // value can't push the modal card off the visible area entirely.
-    let top_logical = (insets.top / scale).min(window_height * 0.25);
-    let bottom_logical = (insets.bottom / scale).min(window_height * 0.25);
+    // Physical insets are pre-divided by the UI scale — see
+    // `apply_safe_area_anchors`.
+    let ui = effective_ui_scale(ui_scale.as_deref());
+    let top_logical = (insets.top / scale).min(window_height * 0.25) / ui;
+    let bottom_logical = (insets.bottom / scale).min(window_height * 0.25) / ui;
     for mut node in &mut scrims {
         // Set both edges so the scrim's content box equals the usable area
         // between the status bar and the gesture/navigation bar. With

solitaire_engine/src/settings_plugin/input.rs

@@ -353,6 +353,14 @@ pub(super) fn handle_settings_buttons(
                     **t = on_off_label(settings.0.reduce_motion_mode);
                 }
             }
+            SettingsButton::ToggleReduceTransparency => {
+                settings.0.reduce_transparency_mode = !settings.0.reduce_transparency_mode;
+                persist(&path, &settings.0);
+                changed.write(SettingsChangedEvent(settings.0.clone()));
+                // Text refreshed by `update_reduce_transparency_text`; the
+                // glass chrome itself follows via `update_glass_surfaces`
+                // next frame.
+            }
             SettingsButton::ToggleTouchInputMode => {
                 use solitaire_data::settings::TouchInputMode;
                 settings.0.touch_input_mode = match settings.0.touch_input_mode {
@@ -363,6 +371,14 @@ pub(super) fn handle_settings_buttons(
                 changed.write(SettingsChangedEvent(settings.0.clone()));
                 // Text refreshed by `update_touch_input_mode_text` next frame.
             }
+            SettingsButton::CycleUiScale => {
+                settings.0.ui_scale = next_ui_scale(settings.0.ui_scale);
+                persist(&path, &settings.0);
+                changed.write(SettingsChangedEvent(settings.0.clone()));
+                // Text refreshed by `update_ui_scale_text`; the live
+                // `bevy::ui::UiScale` resource follows via
+                // `sync_ui_scale_resource` next frame.
+            }
             SettingsButton::ToggleWinnableDealsOnly => {
                 settings.0.winnable_deals_only = !settings.0.winnable_deals_only;
                 persist(&path, &settings.0);

solitaire_engine/src/settings_plugin/mod.rs

@@ -135,10 +135,18 @@ struct HighContrastText;
 #[derive(Component, Debug)]
 struct ReduceMotionText;
 
+/// Marks the `Text` node showing the current reduce-transparency state.
+#[derive(Component, Debug)]
+struct ReduceTransparencyText;
+
 /// Marks the `Text` node showing the current touch input mode state.
 #[derive(Component, Debug)]
 struct TouchInputModeText;
 
+/// Marks the `Text` node showing the current UI scale percentage.
+#[derive(Component, Debug)]
+struct UiScaleText;
+
 /// Marks the `Text` node showing the live tooltip-delay value.
 #[derive(Component, Debug)]
 struct TooltipDelayText;
@@ -273,10 +281,18 @@ enum SettingsButton {
     /// non-essential motion (card-slide animations become instant
     /// snaps) per `design-system.md` §Accessibility (#3).
     ToggleReduceMotion,
+    /// Toggle the [`Settings::reduce_transparency_mode`] flag — swaps
+    /// translucent glass chrome (the floating touch tab bar) for opaque
+    /// fills so table content never bleeds through UI text.
+    ToggleReduceTransparency,
     /// Toggle [`Settings::touch_input_mode`] between `OneTap`
     /// (auto-move on tap, default) and `TapToSelect` (first tap selects
     /// a card/stack, second tap on a target pile moves it).
     ToggleTouchInputMode,
+    /// Cycle [`Settings::ui_scale`] through 90 % → 100 % → 115 % →
+    /// 130 % → 90 %. Applied live via `bevy::ui::UiScale`; the table
+    /// stays window-fit (Phase K).
+    CycleUiScale,
     /// Toggle the [`Settings::winnable_deals_only`] flag. When on, new
     /// random Classic-mode deals are filtered through
     /// [`solitaire_core::game_state::GameState::solve_fresh_deal`] until one is provably
@@ -353,7 +369,9 @@ impl SettingsButton {
             // run before continuing to the picker rows.
             SettingsButton::ToggleHighContrast => 61,
             SettingsButton::ToggleReduceMotion => 62,
-            SettingsButton::ToggleTouchInputMode => 63,
+            SettingsButton::ToggleReduceTransparency => 63,
+            SettingsButton::ToggleTouchInputMode => 64,
+            SettingsButton::CycleUiScale => 65,
             // Picker rows — every swatch in a row shares the row's
             // priority so entity-index tiebreaking yields left → right.
             SettingsButton::SelectCardBack(_) => 70,
@@ -449,6 +467,11 @@ impl Plugin for SettingsPlugin {
                     handle_volume_keys,
                     record_window_geometry_changes,
                     persist_window_geometry_after_debounce,
+                    // State sync, not UI — runs even under `headless()`
+                    // so the live `bevy::ui::UiScale` always mirrors the
+                    // setting; rides the mutator spine so it is ordered
+                    // after every settings writer this frame.
+                    sync_ui_scale_resource,
                 )
                     .chain()
                     .in_set(SettingsMutation),
@@ -492,6 +515,7 @@ impl Plugin for SettingsPlugin {
                     update_high_contrast_backgrounds.run_if(resource_changed::<SettingsResource>),
                     update_reduce_motion_text,
                     update_touch_input_mode_text,
+                    update_ui_scale_text,
                     update_tooltip_delay_text,
                     update_time_bonus_multiplier_text,
                     update_replay_move_interval_text,
@@ -499,6 +523,16 @@ impl Plugin for SettingsPlugin {
                     update_smart_default_size_text,
                 ),
             );
+            app.add_systems(
+                Update,
+                (
+                    update_reduce_transparency_text,
+                    // Guards internally on settings-change / newly added
+                    // glass — `Added<GlassSurface>` can't be expressed as
+                    // a resource run condition.
+                    update_glass_surfaces,
+                ),
+            );
             app.add_systems(
                 Update,
                 (

solitaire_engine/src/settings_plugin/tests.rs

@@ -736,3 +736,60 @@ fn scroll_clamps_offset_to_zero_at_top() {
         "scrolling past top must clamp to 0, got {offset}"
     );
 }
+
+// ---------------------------------------------------------------------------
+// Phase K: UI scale
+// ---------------------------------------------------------------------------
+
+#[test]
+fn ui_scale_steps_cycle_and_wrap() {
+    assert_eq!(next_ui_scale(0.9), 1.0);
+    assert_eq!(next_ui_scale(1.0), 1.15);
+    assert_eq!(next_ui_scale(1.15), 1.3);
+    assert_eq!(next_ui_scale(1.3), 0.9, "the cycle must wrap");
+    // A hand-edited in-between value advances to the next larger step.
+    assert_eq!(next_ui_scale(1.05), 1.15);
+}
+
+#[test]
+fn ui_scale_label_formats_as_percent() {
+    assert_eq!(ui_scale_label(0.9), "90%");
+    assert_eq!(ui_scale_label(1.0), "100%");
+    assert_eq!(ui_scale_label(1.15), "115%");
+    assert_eq!(ui_scale_label(1.3), "130%");
+}
+
+#[test]
+fn ui_scale_setting_syncs_the_bevy_resource() {
+    let mut app = headless_app();
+    app.insert_resource(UiScale(1.0));
+    app.world_mut()
+        .resource_mut::<SettingsResource>()
+        .0
+        .ui_scale = 1.3;
+    app.update();
+
+    assert!(
+        (app.world().resource::<UiScale>().0 - 1.3).abs() < f32::EPSILON,
+        "Settings::ui_scale must drive bevy::ui::UiScale"
+    );
+}
+
+#[test]
+fn ui_scale_out_of_range_sanitizes_on_load() {
+    use solitaire_data::settings::{UI_SCALE_MAX, UI_SCALE_MIN};
+
+    let wild = Settings {
+        ui_scale: 5.0,
+        ..Settings::default()
+    }
+    .sanitized();
+    assert_eq!(wild.ui_scale, UI_SCALE_MAX);
+
+    let tiny = Settings {
+        ui_scale: 0.1,
+        ..Settings::default()
+    }
+    .sanitized();
+    assert_eq!(tiny.ui_scale, UI_SCALE_MIN);
+}

solitaire_engine/src/settings_plugin/ui.rs

@@ -317,6 +317,15 @@ fn spawn_accessibility_tab(
         "Skips card-slide animations and other non-essential motion. Cards snap instantly to their target.",
         font_res,
     );
+    toggle_row(
+        body,
+        "Reduce Transparency",
+        ReduceTransparencyText,
+        on_off_label(settings.reduce_transparency_mode),
+        SettingsButton::ToggleReduceTransparency,
+        "Replaces the see-through glass toolbar with a solid panel so cards behind it never reduce readability.",
+        font_res,
+    );
     toggle_row(
         body,
         "Touch Input Mode",
@@ -326,6 +335,15 @@ fn spawn_accessibility_tab(
         "One-tap: tap a card to auto-move it. Tap to select: first tap selects a card, second tap on a pile moves it.",
         font_res,
     );
+    toggle_row(
+        body,
+        "UI Scale",
+        UiScaleText,
+        ui_scale_label(settings.ui_scale),
+        SettingsButton::CycleUiScale,
+        "Scales all menus, buttons, and HUD text. The table itself always fits the screen.",
+        font_res,
+    );
     tooltip_delay_row(body, settings.tooltip_delay_secs, font_res);
 }
 

solitaire_engine/src/settings_plugin/updates.rs

@@ -9,8 +9,10 @@ use crate::font_plugin::FontResource;
 use crate::progress_plugin::ProgressResource;
 use crate::resources::{SettingsScrollPos, SyncStatus, SyncStatusResource};
 use crate::theme::ThemeThumbnailCache;
+use crate::ui_glass::{GlassSurface, glass_decorations};
 use crate::ui_modal::ModalScrim;
 use crate::ui_theme::{BORDER_SUBTLE_HC, HighContrastBackground, HighContrastBorder};
+use bevy::ui::{BackgroundGradient, BorderGradient};
 
 /// Spawns the Settings panel when `SettingsScreen` becomes `true`;
 /// despawns it when it becomes `false`.
@@ -330,6 +332,41 @@ pub(super) fn update_reduce_motion_text(
     }
 }
 
+pub(super) fn update_reduce_transparency_text(
+    settings: Res<SettingsResource>,
+    mut text_nodes: Query<&mut Text, With<ReduceTransparencyText>>,
+) {
+    if !settings.is_changed() {
+        return;
+    }
+    for mut text in &mut text_nodes {
+        **text = on_off_label(settings.0.reduce_transparency_mode);
+    }
+}
+
+/// Retargets every [`GlassSurface`]'s sheen + rim gradients when the
+/// reduce-transparency or high-contrast toggles change. Runs on
+/// `SettingsResource` change and on newly added surfaces (so glass
+/// spawned after startup picks up an already-active toggle). Parallel to
+/// [`update_high_contrast_borders`]: same trigger, different components.
+pub(super) fn update_glass_surfaces(
+    settings: Res<SettingsResource>,
+    mut surfaces: Query<(&mut BackgroundGradient, &mut BorderGradient), With<GlassSurface>>,
+    added: Query<(), Added<GlassSurface>>,
+) {
+    if !settings.is_changed() && added.is_empty() {
+        return;
+    }
+    let (sheen, rim) = glass_decorations(
+        settings.0.reduce_transparency_mode,
+        settings.0.high_contrast_mode,
+    );
+    for (mut s, mut r) in &mut surfaces {
+        *s = sheen.clone();
+        *r = rim.clone();
+    }
+}
+
 pub(super) fn update_touch_input_mode_text(
     settings: Res<SettingsResource>,
     mut text_nodes: Query<&mut Text, With<TouchInputModeText>>,
@@ -515,6 +552,58 @@ pub(super) fn touch_input_mode_label(mode: &solitaire_data::settings::TouchInput
     }
 }
 
+/// The four UI-scale steps the settings row cycles through (Phase K).
+pub(super) const UI_SCALE_STEPS: [f32; 4] = [0.9, 1.0, 1.15, 1.3];
+
+/// The next UI-scale step after `current`, wrapping 130 % → 90 %. A
+/// hand-edited value between steps advances to the first step larger
+/// than it, so the cycle always makes visible progress.
+pub(super) fn next_ui_scale(current: f32) -> f32 {
+    for step in UI_SCALE_STEPS {
+        if step > current + 0.001 {
+            return step;
+        }
+    }
+    UI_SCALE_STEPS[0]
+}
+
+/// Display string for the UI-scale row, e.g. `"115%"`.
+pub(super) fn ui_scale_label(scale: f32) -> String {
+    format!("{:.0}%", scale * 100.0)
+}
+
+/// Refreshes the live UI-scale value text whenever settings change.
+pub(super) fn update_ui_scale_text(
+    settings: Res<SettingsResource>,
+    mut text_nodes: Query<&mut Text, With<UiScaleText>>,
+) {
+    if !settings.is_changed() {
+        return;
+    }
+    for mut text in &mut text_nodes {
+        **text = ui_scale_label(settings.0.ui_scale);
+    }
+}
+
+/// Applies `Settings::ui_scale` to the live [`bevy::ui::UiScale`]
+/// resource — at startup (first change tick) and whenever the setting
+/// changes. Absent under `MinimalPlugins` (no `bevy_ui`), hence the
+/// `Option`; the table is unaffected either way (`compute_layout`
+/// owns world-space sizing, not UI scale).
+pub(super) fn sync_ui_scale_resource(
+    settings: Res<SettingsResource>,
+    ui_scale: Option<ResMut<UiScale>>,
+) {
+    let Some(mut ui_scale) = ui_scale else { return };
+    if !settings.is_changed() {
+        return;
+    }
+    let target = settings.0.ui_scale;
+    if (ui_scale.0 - target).abs() > f32::EPSILON {
+        ui_scale.0 = target;
+    }
+}
+
 /// Display string for the "Smart window size" toggle. The argument
 /// is the *enabled* state (i.e. the inverse of the underlying
 /// `disable_smart_default_size` field) so reading the label gives

solitaire_engine/src/stats_plugin.rs

@@ -30,7 +30,7 @@ use crate::ui_modal::{ButtonVariant, ModalButton, spawn_modal_button};
 use crate::ui_theme::{
     ACCENT_PRIMARY, BG_ELEVATED_HI, BORDER_SUBTLE, HighContrastBorder, RADIUS_SM, STATE_INFO,
     STATE_WARNING, STREAK_MILESTONES, TEXT_PRIMARY, TEXT_SECONDARY, TYPE_BODY, TYPE_BODY_LG,
-    TYPE_CAPTION, TYPE_HEADLINE, VAL_SPACE_1, VAL_SPACE_2, VAL_SPACE_3, VAL_SPACE_4,
+    TYPE_HEADLINE, VAL_SPACE_1, VAL_SPACE_2, VAL_SPACE_3, VAL_SPACE_4,
 };
 
 /// Bevy resource wrapping the current stats.
@@ -719,25 +719,17 @@ pub(crate) fn spawn_stats_body(
             },
         ))
         .with_children(|body| {
-            // First-launch caption — sits above the grid as gentle nudge so
+            // First-launch empty state (Phase L) — sits above the grid so
             // the wall of em-dashes reads as "nothing to track yet" rather
             // than as broken state.
             if is_first_launch {
-                body.spawn((
-                    Text::new("Play a game to start tracking stats."),
-                    TextFont {
-                        font_size: TYPE_CAPTION,
-                        ..default()
-                    },
-                    TextColor(TEXT_SECONDARY),
-                    Node {
-                        margin: UiRect {
-                            bottom: VAL_SPACE_2,
-                            ..default()
-                        },
-                        ..default()
-                    },
-                ));
+                crate::ui_modal::spawn_empty_state(
+                    body,
+                    "\u{2663}",
+                    "Play a game to start tracking stats.",
+                    None,
+                    font_res,
+                );
             }
 
             // --- primary stat cells grid ---
@@ -893,6 +885,20 @@ pub(crate) fn spawn_replays_body(
     selected_index: usize,
     font_res: Option<&FontResource>,
 ) {
+    // Standard empty state (Phase L) — the selector / Watch / Copy
+    // controls only spawn when there is something to select, so their
+    // handlers all no-op via their existing empty-query paths.
+    if replays.is_empty() {
+        crate::ui_modal::spawn_empty_state(
+            card,
+            "\u{2666}",
+            "No replays yet.",
+            Some("Every win records a replay here automatically."),
+            font_res,
+        );
+        return;
+    }
+
     let font_handle = font_res.map(|f| f.0.clone()).unwrap_or_default();
     let font_row = TextFont {
         font: font_handle,

solitaire_engine/src/theme_store_plugin.rs

@@ -32,8 +32,8 @@ use crate::resources::TokioRuntimeResource;
 use crate::settings_plugin::{SettingsPanel, SettingsResource};
 use crate::theme::{ImportError, ThemeRegistry, import_theme, refresh_registry};
 use crate::ui_modal::{
-    ButtonVariant, ModalScrim, ScrimDismissible, spawn_modal, spawn_modal_actions,
-    spawn_modal_button, spawn_modal_header,
+    ButtonVariant, ModalScrim, ScrimDismissible, spawn_empty_state, spawn_modal,
+    spawn_modal_actions, spawn_modal_button, spawn_modal_header,
 };
 use crate::ui_theme::{
     BORDER_SUBTLE, TEXT_PRIMARY, TEXT_SECONDARY, TYPE_BODY, TYPE_CAPTION, VAL_SPACE_2, VAL_SPACE_3,
@@ -528,25 +528,31 @@ fn spawn_store_modal(
 
         match catalog_state {
             CatalogState::Idle | CatalogState::Loading => {
-                card.spawn((
-                    Text::new("Loading catalog…"),
-                    body_font.clone(),
-                    TextColor(TEXT_SECONDARY),
-                ));
+                spawn_empty_state(
+                    card,
+                    "\u{21BB}",
+                    "Loading the catalog\u{2026}",
+                    None,
+                    font_res,
+                );
             }
             CatalogState::Error(msg) => {
-                card.spawn((
-                    Text::new(format!("Could not load the catalog: {msg}")),
-                    body_font.clone(),
-                    TextColor(TEXT_SECONDARY),
-                ));
+                spawn_empty_state(
+                    card,
+                    "!",
+                    "Couldn't load the catalog.",
+                    Some(msg.as_str()),
+                    font_res,
+                );
             }
             CatalogState::Loaded(entries) if entries.is_empty() => {
-                card.spawn((
-                    Text::new("The server has no themes yet."),
-                    body_font.clone(),
-                    TextColor(TEXT_SECONDARY),
-                ));
+                spawn_empty_state(
+                    card,
+                    "#",
+                    "The server has no themes yet.",
+                    Some("Themes dropped into the server's theme_store folder appear here."),
+                    font_res,
+                );
             }
             CatalogState::Loaded(entries) => {
                 for entry in entries {

solitaire_engine/src/ui_glass.rs

@@ -0,0 +1,281 @@
+//! "Liquid glass" material for floating UI surfaces.
+//!
+//! Produces the translucent, light-catching treatment used by the floating
+//! touch tab bar (`hud_plugin::tab_bar`): a semi-transparent fill with a
+//! vertical sheen, a specular rim highlight around the border, and a soft
+//! drop shadow underneath. The table shows through the fill *sharp* — Bevy's
+//! UI pipeline has no backdrop-blur concept, so this module approximates
+//! frosted glass with layered gradients instead of sampling what's behind
+//! the node. That keeps it a plain `bevy_ui` bundle: no custom shaders, no
+//! extra render passes, and identical behaviour on desktop, Android, and
+//! WebGL2.
+//!
+//! # Swapping the treatment
+//!
+//! Layout code depends only on [`glass_surface`] and [`GLASS_BORDER_PX`].
+//! A future real-refraction material (e.g. a `UiMaterial` sampling a blurred
+//! render target) can replace this module's internals without touching any
+//! caller — that boundary is the reason this file exists separately from
+//! `hud_plugin/tab_bar.rs`.
+//!
+//! # Departure from the Terminal design system
+//!
+//! `ui_theme` documents HUD chrome as opaque "status-line" panels. The glass
+//! bar is a deliberate, user-approved exception for the floating touch tab
+//! bar only; do not reuse this material for modals or the top HUD band
+//! without a matching design decision.
+
+use bevy::prelude::*;
+use bevy::ui::{
+    BackgroundGradient, BorderGradient, BoxShadow, ColorStop, LinearGradient, ShadowStyle,
+};
+
+use crate::ui_theme::{BG_ELEVATED, BORDER_SUBTLE, BORDER_SUBTLE_HC};
+
+/// Border width every glass surface must reserve in its `Node::border` so
+/// the rim gradient has a strip to paint into.
+pub const GLASS_BORDER_PX: f32 = 1.0;
+
+/// Marker on every node that received [`glass_surface`]. The settings
+/// plugin's `update_glass_surfaces` retargets these when the player
+/// toggles reduce-transparency or high-contrast, swapping the gradients
+/// in place via [`glass_decorations`].
+#[derive(Component, Debug)]
+pub struct GlassSurface;
+
+/// Base fill at the *bottom* of the glass sheet — near-black at ~62%
+/// opacity so the felt and cards remain visible through the bar while
+/// keeping icon/label contrast comfortable.
+const GLASS_FILL_BOTTOM: Color = Color::srgba(0.055, 0.055, 0.063, 0.62);
+
+/// Fill at the *top* of the sheet — the same glass lifted towards white,
+/// reading as the curved surface catching overhead light.
+const GLASS_FILL_TOP: Color = Color::srgba(0.20, 0.21, 0.23, 0.66);
+
+/// Rim highlight at the top edge — the bright specular line where a real
+/// glass pill would catch the light source.
+const GLASS_RIM_TOP: Color = Color::srgba(1.0, 1.0, 1.0, 0.38);
+
+/// Rim at the midpoint — almost gone, so the highlight reads as a glint
+/// rather than a drawn outline.
+const GLASS_RIM_MID: Color = Color::srgba(1.0, 1.0, 1.0, 0.06);
+
+/// Rim at the bottom edge — a faint secondary catch-light, as on the
+/// underside of a curved surface above a bright table.
+const GLASS_RIM_BOTTOM: Color = Color::srgba(1.0, 1.0, 1.0, 0.16);
+
+/// Drop shadow under the floating surface.
+const GLASS_SHADOW: Color = Color::srgba(0.0, 0.0, 0.0, 0.35);
+
+/// High-contrast fill — same glass, far less see-through, so text and
+/// icons keep contrast over any card art. Per `design-system.md`
+/// §Accessibility the HC toggle trades aesthetics for legibility.
+const GLASS_FILL_TOP_HC: Color = Color::srgba(0.20, 0.21, 0.23, 0.90);
+/// High-contrast fill at the bottom of the sheet.
+const GLASS_FILL_BOTTOM_HC: Color = Color::srgba(0.055, 0.055, 0.063, 0.88);
+
+/// High-contrast rim at the top edge — matches the luminance of
+/// `BORDER_SUBTLE_HC` so the bar's outline reads as strongly as every
+/// other HC-boosted border.
+const GLASS_RIM_TOP_HC: Color = Color::srgba(1.0, 1.0, 1.0, 0.75);
+/// High-contrast rim at the midpoint.
+const GLASS_RIM_MID_HC: Color = Color::srgba(1.0, 1.0, 1.0, 0.35);
+/// High-contrast rim at the bottom edge.
+const GLASS_RIM_BOTTOM_HC: Color = Color::srgba(1.0, 1.0, 1.0, 0.50);
+
+/// Visual components for a floating glass surface.
+///
+/// The caller owns the `Node` and must set two fields for the material to
+/// render correctly:
+/// - `border: UiRect::all(Val::Px(GLASS_BORDER_PX))` — the rim gradient
+///   paints into the border strip and is invisible without it.
+/// - `border_radius` — half the node height for a fully-round pill.
+///
+/// Everything here is fragment-shader work inside Bevy's stock UI pipeline,
+/// so it is safe on WebGL2 and adds no per-frame cost beyond ordinary nodes.
+pub fn glass_surface() -> impl Bundle {
+    let (sheen, rim) = glass_decorations(false, false);
+    (
+        GlassSurface,
+        sheen,
+        rim,
+        // Soft shadow underneath sells the "floating above the table" read.
+        BoxShadow(vec![ShadowStyle {
+            color: GLASS_SHADOW,
+            x_offset: Val::Px(0.0),
+            y_offset: Val::Px(6.0),
+            spread_radius: Val::Px(0.0),
+            blur_radius: Val::Px(16.0),
+        }]),
+    )
+}
+
+/// The sheen + rim pair for the requested accessibility state. The
+/// settings plugin overwrites every [`GlassSurface`]'s components with
+/// these when the relevant toggles change.
+///
+/// - Default: translucent fill with a top-lit sheen and a specular rim.
+/// - `high_contrast`: same shape, near-opaque fill, and a rim boosted to
+///   `BORDER_SUBTLE_HC` luminance so the outline stays legible.
+/// - `reduce_transparency`: flat opaque `BG_ELEVATED` fill and a flat
+///   border — no see-through at all. Combined with `high_contrast` the
+///   flat border brightens to `BORDER_SUBTLE_HC`.
+pub fn glass_decorations(
+    reduce_transparency: bool,
+    high_contrast: bool,
+) -> (BackgroundGradient, BorderGradient) {
+    if reduce_transparency {
+        // "Gradients" with a single stop render as flat fills — reusing the
+        // same component types means the settings toggle swaps values, not
+        // component sets.
+        let border = if high_contrast {
+            BORDER_SUBTLE_HC
+        } else {
+            BORDER_SUBTLE
+        };
+        return (
+            BackgroundGradient(vec![
+                LinearGradient::new(
+                    LinearGradient::TO_BOTTOM,
+                    vec![ColorStop::new(BG_ELEVATED, Val::Percent(0.0))],
+                )
+                .into(),
+            ]),
+            BorderGradient(vec![
+                LinearGradient::new(
+                    LinearGradient::TO_BOTTOM,
+                    vec![ColorStop::new(border, Val::Percent(0.0))],
+                )
+                .into(),
+            ]),
+        );
+    }
+
+    let (fill_top, fill_bottom, rim_top, rim_mid, rim_bottom) = if high_contrast {
+        (
+            GLASS_FILL_TOP_HC,
+            GLASS_FILL_BOTTOM_HC,
+            GLASS_RIM_TOP_HC,
+            GLASS_RIM_MID_HC,
+            GLASS_RIM_BOTTOM_HC,
+        )
+    } else {
+        (
+            GLASS_FILL_TOP,
+            GLASS_FILL_BOTTOM,
+            GLASS_RIM_TOP,
+            GLASS_RIM_MID,
+            GLASS_RIM_BOTTOM,
+        )
+    };
+    (
+        // Sheen: one top-to-bottom linear gradient carries both the fill and
+        // the lighting so there is a single source of truth for the surface
+        // colour (a separate `BackgroundColor` would just be painted over).
+        BackgroundGradient(vec![
+            LinearGradient::new(
+                LinearGradient::TO_BOTTOM,
+                vec![
+                    ColorStop::new(fill_top, Val::Percent(0.0)),
+                    ColorStop::new(fill_bottom, Val::Percent(60.0)),
+                ],
+            )
+            .into(),
+        ]),
+        // Specular rim: bright at the top edge, fading out through the
+        // sides, with a faint return at the bottom.
+        BorderGradient(vec![
+            LinearGradient::new(
+                LinearGradient::TO_BOTTOM,
+                vec![
+                    ColorStop::new(rim_top, Val::Percent(0.0)),
+                    ColorStop::new(rim_mid, Val::Percent(55.0)),
+                    ColorStop::new(rim_bottom, Val::Percent(100.0)),
+                ],
+            )
+            .into(),
+        ]),
+    )
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use bevy::ui::Gradient;
+
+    /// The bundle must insert all three visual components — a regression
+    /// here (e.g. a refactor dropping the rim) would silently flatten the
+    /// glass into a plain translucent box.
+    #[test]
+    fn glass_surface_inserts_sheen_rim_and_shadow() {
+        let mut world = World::new();
+        let e = world.spawn(glass_surface()).id();
+        assert!(world.get::<BackgroundGradient>(e).is_some());
+        assert!(world.get::<BorderGradient>(e).is_some());
+        assert!(world.get::<BoxShadow>(e).is_some());
+    }
+
+    /// The fill must stay translucent (that is the whole point of glass) but
+    /// opaque enough that text keeps contrast over busy card art.
+    #[test]
+    fn glass_fill_alpha_stays_in_readable_band() {
+        for fill in [GLASS_FILL_TOP, GLASS_FILL_BOTTOM] {
+            let a = fill.alpha();
+            assert!(
+                (0.4..=0.85).contains(&a),
+                "glass fill alpha {a} outside readable 0.4–0.85 band"
+            );
+        }
+    }
+
+    /// The rim gradient must actually glint: strictly brightest at the top,
+    /// dimmest in the middle.
+    #[test]
+    fn rim_highlight_peaks_at_top() {
+        assert!(GLASS_RIM_TOP.alpha() > GLASS_RIM_BOTTOM.alpha());
+        assert!(GLASS_RIM_BOTTOM.alpha() > GLASS_RIM_MID.alpha());
+        assert!(GLASS_RIM_TOP_HC.alpha() > GLASS_RIM_BOTTOM_HC.alpha());
+        assert!(GLASS_RIM_BOTTOM_HC.alpha() > GLASS_RIM_MID_HC.alpha());
+    }
+
+    /// Reduce-transparency must produce fully opaque fills — the entire
+    /// point of the toggle is that nothing shows through.
+    #[test]
+    fn reduce_transparency_is_fully_opaque() {
+        for high_contrast in [false, true] {
+            let (sheen, _) = glass_decorations(true, high_contrast);
+            for gradient in &sheen.0 {
+                let Gradient::Linear(linear) = gradient else {
+                    panic!("reduce-transparency sheen must stay linear");
+                };
+                for stop in &linear.stops {
+                    assert_eq!(
+                        stop.color.alpha(),
+                        1.0,
+                        "opaque variant leaked translucency (hc={high_contrast})"
+                    );
+                }
+            }
+        }
+    }
+
+    /// High-contrast glass must be meaningfully less transparent than the
+    /// default, and its rim meaningfully brighter — otherwise the toggle
+    /// does nothing perceptible on this surface.
+    #[test]
+    fn high_contrast_boosts_fill_and_rim() {
+        assert!(GLASS_FILL_TOP_HC.alpha() >= GLASS_FILL_TOP.alpha() + 0.15);
+        assert!(GLASS_FILL_BOTTOM_HC.alpha() >= GLASS_FILL_BOTTOM.alpha() + 0.15);
+        assert!(GLASS_RIM_TOP_HC.alpha() >= GLASS_RIM_TOP.alpha() + 0.25);
+    }
+
+    /// `glass_surface()` must carry the marker the settings applier
+    /// retargets — without it the accessibility toggles silently skip
+    /// the bar.
+    #[test]
+    fn glass_surface_carries_retarget_marker() {
+        let mut world = World::new();
+        let e = world.spawn(glass_surface()).id();
+        assert!(world.get::<GlassSurface>(e).is_some());
+    }
+}

solitaire_engine/src/ui_modal.rs

@@ -60,9 +60,9 @@ use crate::settings_plugin::SettingsResource;
 use crate::ui_theme::{
     ACCENT_PRIMARY, ACCENT_PRIMARY_HOVER, ACCENT_SECONDARY, BG_BASE, BG_ELEVATED, BG_ELEVATED_HI,
     BG_ELEVATED_PRESSED, BG_ELEVATED_TOP, BORDER_STRONG, BORDER_SUBTLE, HighContrastBorder,
-    MOTION_MODAL_SECS, RADIUS_LG, RADIUS_MD, RADIUS_SM, SCRIM, STATE_SUCCESS, TEXT_PRIMARY,
-    TEXT_SECONDARY, TYPE_BODY_LG, TYPE_CAPTION, TYPE_HEADLINE, VAL_SPACE_2, VAL_SPACE_3,
-    VAL_SPACE_4, VAL_SPACE_5, scaled_duration,
+    MOTION_MODAL_SECS, RADIUS_LG, RADIUS_MD, RADIUS_SM, SCRIM, STATE_SUCCESS, TEXT_DISABLED,
+    TEXT_PRIMARY, TEXT_SECONDARY, TYPE_BODY, TYPE_BODY_LG, TYPE_CAPTION, TYPE_DISPLAY,
+    TYPE_HEADLINE, VAL_SPACE_2, VAL_SPACE_3, VAL_SPACE_4, VAL_SPACE_5, scaled_duration,
 };
 
 // ---------------------------------------------------------------------------
@@ -328,6 +328,80 @@ pub fn spawn_modal_body_text(
     parent.spawn((ModalBody, Text::new(text.into()), font, TextColor(color)));
 }
 
+/// Standard empty / loading / error surface (Phase L): a large glyph,
+/// a headline, and an optional secondary detail line, centred in the
+/// available space. Every async or possibly-empty surface (leaderboard,
+/// replays, theme store, first-launch stats) renders through this so
+/// "nothing here yet" reads identically everywhere.
+///
+/// A next-step action is composition, not configuration: spawn a
+/// [`spawn_modal_button`] (or any control) in the same parent right
+/// after this call.
+///
+/// `glyph` MUST come from FiraMono-covered ranges — card suits
+/// (U+2660–2666), Arrows (U+2190–21FF), or ASCII. The Geometric Shapes
+/// block renders as tofu on Android (§10 / §11).
+pub fn spawn_empty_state(
+    parent: &mut ChildSpawnerCommands,
+    glyph: &str,
+    headline: &str,
+    detail: Option<&str>,
+    font_res: Option<&FontResource>,
+) {
+    let font_handle = font_res.map(|f| f.0.clone()).unwrap_or_default();
+    let font_glyph = TextFont {
+        font: font_handle.clone(),
+        font_size: TYPE_DISPLAY,
+        ..default()
+    };
+    let font_headline = TextFont {
+        font: font_handle.clone(),
+        font_size: TYPE_BODY_LG,
+        ..default()
+    };
+    let font_detail = TextFont {
+        font: font_handle,
+        font_size: TYPE_BODY,
+        ..default()
+    };
+
+    parent
+        .spawn((
+            EmptyStateBlock,
+            Node {
+                flex_direction: FlexDirection::Column,
+                align_items: AlignItems::Center,
+                row_gap: VAL_SPACE_2,
+                padding: UiRect::axes(VAL_SPACE_3, VAL_SPACE_5),
+                width: Val::Percent(100.0),
+                ..default()
+            },
+        ))
+        .with_children(|block| {
+            block.spawn((
+                Text::new(glyph.to_string()),
+                font_glyph,
+                TextColor(TEXT_DISABLED),
+            ));
+            block.spawn((
+                Text::new(headline.to_string()),
+                font_headline,
+                TextColor(TEXT_PRIMARY),
+            ));
+            if let Some(detail) = detail {
+                block.spawn((
+                    Text::new(detail.to_string()),
+                    font_detail,
+                    TextColor(TEXT_SECONDARY),
+                ));
+            }
+        });
+}
+
+/// Marker on every [`spawn_empty_state`] block, mostly for tests.
+#[derive(Component, Debug)]
+pub struct EmptyStateBlock;
+
 /// Spawns the bottom actions row — flex-row with primary right-aligned.
 /// The closure populates the row's buttons via `spawn_modal_button`.
 ///
@@ -1184,4 +1258,62 @@ mod tests {
             "exactly one of the two stacked dismissible modals should remain"
         );
     }
+
+    // -----------------------------------------------------------------------
+    // Phase L: standard empty state
+    // -----------------------------------------------------------------------
+
+    /// The helper spawns glyph + headline (+ detail when given) under one
+    /// marked block, so every empty surface renders identically.
+    #[test]
+    fn empty_state_spawns_expected_structure() {
+        let mut app = App::new();
+        app.add_plugins(MinimalPlugins);
+        {
+            let world = app.world_mut();
+            let mut commands = world.commands();
+            commands.spawn(Node::default()).with_children(|parent| {
+                spawn_empty_state(
+                    parent,
+                    "\u{2660}",
+                    "Nothing here.",
+                    Some("Do the thing."),
+                    None,
+                );
+                spawn_empty_state(parent, "!", "No detail variant.", None, None);
+            });
+        }
+        app.update();
+
+        let blocks = app
+            .world_mut()
+            .query_filtered::<Entity, With<EmptyStateBlock>>()
+            .iter(app.world())
+            .count();
+        assert_eq!(blocks, 2, "each call spawns exactly one marked block");
+
+        let texts: Vec<String> = app
+            .world_mut()
+            .query::<&Text>()
+            .iter(app.world())
+            .map(|t| t.0.clone())
+            .collect();
+        for expected in [
+            "\u{2660}",
+            "Nothing here.",
+            "Do the thing.",
+            "!",
+            "No detail variant.",
+        ] {
+            assert!(
+                texts.iter().any(|t| t == expected),
+                "missing text node {expected:?}; got {texts:?}"
+            );
+        }
+        assert_eq!(
+            texts.len(),
+            5,
+            "the detail-less variant must not spawn a detail node"
+        );
+    }
 }