From 1d0bafaabb697ba18cdd2c056e727d0a360c456d Mon Sep 17 00:00:00 2001
From: Ilia Denisov <evilcart@gmail.com>
Date: Sat, 6 Jun 2026 10:23:42 +0200
Subject: [PATCH] Stage 17: UI defect fixes (russian variant, Telegram
 theme/nav/banner, reconnect, hint zoom, plaque, history, transitions,
 per-game cache)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

- #6 align the UI variant id to the backend canonical 'russian_scrabble' (type, variants, Lobby, mock, tests) — fixes the New->Russian 400
- #11/#12 inside Telegram force the colour scheme from WebApp.colorScheme (over OS prefers-color-scheme, fixing the Telegram Desktop breakage) and hide the theme switcher
- #14/#15 nav bar takes Telegram's bg; announcement banner gets a dedicated subtle --ad-bg accent token
- #16 suppress the reconnect banner while backgrounded and silently reconnect the live stream on return to the foreground
- #17 hint zoom scrolls to the placement's bounding box, not the top-left
- #19/#20 players plaque: active seat raised with side shadows, others sunk; tap toggles history
- #21/#23 history: scrollbar-gutter:stable (no word jitter); fixed-height drawer pins the bottom shadow to the board
- #3 (UI) disable nudge on the player's own turn
- #18a directional screen slide transitions (forward in from the right, back reveals the lobby)
- #13 per-game in-memory cache: instant render on re-entry + background refresh
- e2e: openGame waits for the slide transition to settle
---
 ui/e2e/game.spec.ts               |  4 ++
 ui/src/App.svelte                 | 73 ++++++++++++++++++++++++-------
 ui/src/app.css                    |  3 ++
 ui/src/components/AdBanner.svelte |  2 +-
 ui/src/game/Chat.svelte           |  6 ++-
 ui/src/game/Game.svelte           | 61 ++++++++++++++++++++++----
 ui/src/lib/app.svelte.ts          | 53 +++++++++++++++++++---
 ui/src/lib/gamecache.ts           | 30 +++++++++++++
 ui/src/lib/mock/alphabet.ts       |  2 +-
 ui/src/lib/mock/client.ts         |  2 +-
 ui/src/lib/mock/data.ts           |  2 +-
 ui/src/lib/model.ts               |  2 +-
 ui/src/lib/premiums.test.ts       |  2 +-
 ui/src/lib/telegram.ts            | 12 +++++
 ui/src/lib/theme.ts               |  5 +++
 ui/src/lib/variants.test.ts       |  4 +-
 ui/src/lib/variants.ts            |  4 +-
 ui/src/screens/Lobby.svelte       |  2 +-
 ui/src/screens/Settings.svelte    | 23 +++++-----
 19 files changed, 239 insertions(+), 53 deletions(-)
 create mode 100644 ui/src/lib/gamecache.ts

diff --git a/ui/e2e/game.spec.ts b/ui/e2e/game.spec.ts
index b38d17f..cce90f7 100644
--- a/ui/e2e/game.spec.ts
+++ b/ui/e2e/game.spec.ts
@@ -10,6 +10,10 @@ async function openGame(page: Page): Promise<void> {
   await page.getByRole('button', { name: /guest/i }).click();
   await page.getByRole('button', { name: /Ann/ }).click(); // the seeded active game vs Ann
   await expect(page.locator('[data-cell]').first()).toBeVisible();
+  // Wait for the screen-slide transition to settle so only the game pane remains;
+  // until it does, the leaving lobby pane's header (its menu button) is also in the
+  // DOM, which would make shared locators like .burger ambiguous.
+  await expect(page.locator('.pane')).toHaveCount(1);
 }
 
 test('placing a tile and confirming via 🏁 commits the move', async ({ page }) => {
diff --git a/ui/src/App.svelte b/ui/src/App.svelte
index 1acb335..6247051 100644
--- a/ui/src/App.svelte
+++ b/ui/src/App.svelte
@@ -1,5 +1,6 @@
 <script lang="ts">
   import { onMount } from 'svelte';
+  import { cubicOut } from 'svelte/easing';
   import { app, bootstrap } from './lib/app.svelte';
   import { router } from './lib/router.svelte';
   import { t } from './lib/i18n/index.svelte';
@@ -17,28 +18,57 @@
   onMount(() => {
     void bootstrap();
   });
+
+  // Screen transitions: the lobby is the navigation root. Entering a screen from the
+  // lobby slides it in from the right (forward); returning to the lobby slides the
+  // screen out to the right and reveals the lobby (back). Transitions are local, so
+  // they do not play on the initial mount, and collapse to nothing under reduce-motion.
+  const dir = $derived(router.route.name === 'lobby' ? 'back' : 'forward');
+  const enterSign = $derived(dir === 'forward' ? 1 : -1);
+  const leaveSign = $derived(dir === 'forward' ? -1 : 1);
+  const routeKey = $derived(router.route.name + (router.route.params.id ?? ''));
+  const animMs = $derived(app.reduceMotion ? 0 : 260);
+
+  // slideX slides a pane horizontally by a full width. sign>0 enters from / exits to
+  // the right; sign<0 the left. Percentage keeps it viewport-relative without reading
+  // innerWidth, and the .router clips the off-screen pane.
+  function slideX(_node: Element, { duration, sign }: { duration: number; sign: number }) {
+    return {
+      duration,
+      easing: cubicOut,
+      css: (tt: number) => `transform: translateX(${(1 - tt) * sign * 100}%)`,
+    };
+  }
 </script>
 
 {#if !app.ready}
   <div class="splash">{t('common.loading')}</div>
-{:else if router.route.name === 'login'}
-  <Login />
-{:else if router.route.name === 'new'}
-  <NewGame />
-{:else if router.route.name === 'game'}
-  <Game id={router.route.params.id} />
-{:else if router.route.name === 'profile'}
-  <Profile />
-{:else if router.route.name === 'settings'}
-  <Settings />
-{:else if router.route.name === 'about'}
-  <About />
-{:else if router.route.name === 'friends'}
-  <Friends />
-{:else if router.route.name === 'stats'}
-  <Stats />
 {:else}
-  <Lobby />
+  <div class="router">
+    {#key routeKey}
+      <div class="pane" in:slideX={{ duration: animMs, sign: enterSign }} out:slideX={{ duration: animMs, sign: leaveSign }}>
+        {#if router.route.name === 'login'}
+          <Login />
+        {:else if router.route.name === 'new'}
+          <NewGame />
+        {:else if router.route.name === 'game'}
+          <Game id={router.route.params.id} />
+        {:else if router.route.name === 'profile'}
+          <Profile />
+        {:else if router.route.name === 'settings'}
+          <Settings />
+        {:else if router.route.name === 'about'}
+          <About />
+        {:else if router.route.name === 'friends'}
+          <Friends />
+        {:else if router.route.name === 'stats'}
+          <Stats />
+        {:else}
+          <Lobby />
+        {/if}
+      </div>
+    {/key}
+  </div>
 {/if}
 
 <Toast />
@@ -50,4 +80,13 @@
     place-items: center;
     color: var(--text-muted);
   }
+  .router {
+    position: relative;
+    height: 100%;
+    overflow: hidden;
+  }
+  .pane {
+    position: absolute;
+    inset: 0;
+  }
 </style>
diff --git a/ui/src/app.css b/ui/src/app.css
index 2bde4aa..ff1ed3e 100644
--- a/ui/src/app.css
+++ b/ui/src/app.css
@@ -11,6 +11,7 @@
   --bg-elev: #ffffff;
   --surface: #ffffff;
   --surface-2: #eef0f3;
+  --ad-bg: #e3e7ee; /* announcement banner: a subtle accent, darker in light theme */
   --text: #14181f;
   --text-muted: #6b7280;
   --border: #d8dce2;
@@ -51,6 +52,7 @@
     --bg-elev: #171a21;
     --surface: #171a21;
     --surface-2: #1f242d;
+    --ad-bg: #272f3c; /* announcement banner: a subtle accent, lighter in dark theme */
     --text: #e7eaf0;
     --text-muted: #9aa3b2;
     --border: #2a313c;
@@ -82,6 +84,7 @@
   --bg-elev: #171a21;
   --surface: #171a21;
   --surface-2: #1f242d;
+  --ad-bg: #272f3c; /* announcement banner: a subtle accent, lighter in dark theme */
   --text: #e7eaf0;
   --text-muted: #9aa3b2;
   --border: #2a313c;
diff --git a/ui/src/components/AdBanner.svelte b/ui/src/components/AdBanner.svelte
index 843d2b0..e5d2e04 100644
--- a/ui/src/components/AdBanner.svelte
+++ b/ui/src/components/AdBanner.svelte
@@ -57,7 +57,7 @@
     overflow: hidden;
     white-space: nowrap;
     padding: 6px 0;
-    background: var(--surface-2);
+    background: var(--ad-bg);
     color: var(--text-muted);
     font-size: 0.85rem;
     line-height: 1.2;
diff --git a/ui/src/game/Chat.svelte b/ui/src/game/Chat.svelte
index 638f6b5..1cad5c0 100644
--- a/ui/src/game/Chat.svelte
+++ b/ui/src/game/Chat.svelte
@@ -6,12 +6,16 @@
     messages,
     myId,
     busy,
+    canNudge = true,
     onsend,
     onnudge,
   }: {
     messages: ChatMessage[];
     myId: string;
     busy: boolean;
+    // Nudging only makes sense while waiting on the opponent; it is disabled on the
+    // player's own turn (there is no one to hurry along).
+    canNudge?: boolean;
     onsend: (text: string) => void;
     onnudge: () => void;
   } = $props();
@@ -47,7 +51,7 @@
       onkeydown={(e) => e.key === 'Enter' && send()}
     />
     <button class="iconbtn" onclick={send} disabled={busy} aria-label={t('chat.send')}>⬆️</button>
-    <button class="iconbtn" onclick={onnudge} disabled={busy} aria-label={t('chat.nudge')}>🛎️</button>
+    <button class="iconbtn" onclick={onnudge} disabled={busy || !canNudge} aria-label={t('chat.nudge')}>🛎️</button>
   </div>
 </div>
 
diff --git a/ui/src/game/Game.svelte b/ui/src/game/Game.svelte
index 2aebef7..dd82a80 100644
--- a/ui/src/game/Game.svelte
+++ b/ui/src/game/Game.svelte
@@ -18,6 +18,7 @@
   import { alphabetLetters, hasAlphabet } from '../lib/alphabet';
   import { canCheckWord, sanitizeCheckWord } from '../lib/checkword';
   import { shareOrDownloadGcg } from '../lib/share';
+  import { getCachedGame, setCachedGame } from '../lib/gamecache';
   import {
     BLANK,
     newPlacement,
@@ -94,6 +95,7 @@
       ]);
       view = st;
       moves = hist.moves;
+      setCachedGame(id, st, hist.moves);
       placement = newPlacement(st.rack);
       preview = null;
       selected = null;
@@ -109,7 +111,17 @@
       handleError(e);
     }
   }
-  onMount(load);
+  onMount(() => {
+    // Render instantly from the cache (a game opened before), then refresh in the
+    // background. A cold open shows the loading state until load() resolves.
+    const cached = getCachedGame(id);
+    if (cached) {
+      view = cached.view;
+      moves = cached.moves;
+      placement = newPlacement(cached.view.rack);
+    }
+    void load();
+  });
 
   $effect(() => {
     const e = app.lastEvent;
@@ -269,6 +281,17 @@
       const h = await gateway.hint(id);
       if (h.move.tiles.length && view) {
         placement = placementFromHint(h.move.tiles, view.rack);
+        // Scroll the (zoomed) board to the hint's placement rather than the top-left:
+        // focus the centre of the laid tiles' bounding box.
+        const p = placement.pending;
+        if (p.length) {
+          const rows = p.map((tt) => tt.row);
+          const cols = p.map((tt) => tt.col);
+          focus = {
+            row: Math.round((Math.min(...rows) + Math.max(...rows)) / 2),
+            col: Math.round((Math.min(...cols) + Math.max(...cols)) / 2),
+          };
+        }
         if (isCoarse()) zoomed = true;
         view = { ...view, hintsRemaining: h.hintsRemaining };
         recompute();
@@ -428,7 +451,9 @@
   {/snippet}
 
   {#if view}
-    <div class="scoreboard">
+    <!-- svelte-ignore a11y_no_static_element_interactions -->
+    <!-- svelte-ignore a11y_click_events_have_key_events -->
+    <div class="scoreboard" onclick={() => (historyOpen = !historyOpen)}>
       {#each view.game.seats as s (s.seat)}
         <div class="seat" class:turn={view.game.toMove === s.seat && !gameOver} class:win={s.isWinner}>
           <div class="nm">{s.accountId === app.session?.userId ? t('common.you') : s.displayName}</div>
@@ -599,26 +624,39 @@
 
 {#if panel === 'chat'}
   <Modal title={t('game.chat')} onclose={() => (panel = 'none')}>
-    <Chat {messages} myId={app.session?.userId ?? ''} {busy} onsend={sendChat} onnudge={nudge} />
+    <Chat {messages} myId={app.session?.userId ?? ''} {busy} canNudge={!isMyTurn} onsend={sendChat} onnudge={nudge} />
   </Modal>
 {/if}
 
 <style>
   .scoreboard {
     display: flex;
-    gap: 2px;
-    padding: 6px var(--pad);
+    gap: 6px;
+    padding: 8px var(--pad);
     background: var(--bg-elev);
+    cursor: pointer;
   }
   .seat {
     flex: 1;
     text-align: center;
-    padding: 4px;
+    padding: 5px 4px;
     border-radius: var(--radius-sm);
+    background: var(--surface-2);
+    /* inactive seats read as "sunk in" */
+    box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.22);
   }
   .seat.turn {
-    background: var(--surface-2);
-    outline: 1px solid var(--accent);
+    /* the active seat is "raised": lifted clear of the others with side shadows */
+    background: var(--bg-elev);
+    box-shadow:
+      0 1px 2px rgba(0, 0, 0, 0.16),
+      -3px 0 6px -2px rgba(0, 0, 0, 0.26),
+      3px 0 6px -2px rgba(0, 0, 0, 0.26);
+    position: relative;
+    z-index: 1;
+  }
+  .seat.turn .nm {
+    color: var(--accent);
   }
   .seat.win .sc {
     color: var(--ok);
@@ -642,8 +680,13 @@
     position: absolute;
     inset: 0 0 auto 0;
     z-index: 2;
-    max-height: 60%;
+    /* A fixed-height drawer matching the board's slid offset, so the bottom border
+       and its shadow pin to the board immediately instead of tracking the table as
+       moves accumulate. scrollbar-gutter reserves the scrollbar so the centred word
+       column does not jump left/right when the list overflows. */
+    height: 62%;
     overflow: auto;
+    scrollbar-gutter: stable;
     background: var(--surface-2);
     box-shadow: inset 0 -6px 10px -8px rgba(0, 0, 0, 0.5);
     border-bottom: 1px solid var(--border);
diff --git a/ui/src/lib/app.svelte.ts b/ui/src/lib/app.svelte.ts
index 1cde1b6..926b921 100644
--- a/ui/src/lib/app.svelte.ts
+++ b/ui/src/lib/app.svelte.ts
@@ -9,9 +9,10 @@ import { GatewayError } from './client';
 import { navigate, router } from './router.svelte';
 import { errorKey, localeFrom, setLocale, t, type Locale } from './i18n/index.svelte';
 import { applyReduceMotion, applyTelegramTheme, applyTheme, type ThemePref } from './theme';
-import { insideTelegram, onTelegramPath, telegramLaunch } from './telegram';
+import { insideTelegram, onTelegramPath, telegramColorScheme, telegramLaunch } from './telegram';
 import { parseStartParam } from './deeplink';
 import { clearSession, loadPrefs, loadSession, saveSession, savePrefs } from './session';
+import { clearGameCache } from './gamecache';
 import type { BoardLabelMode } from './boardlabels';
 
 export interface Toast {
@@ -47,8 +48,15 @@ export const app = $state<{
 });
 
 let unsubscribeStream: (() => void) | null = null;
+let streamAlive = false;
+let reconnectTimer: ReturnType<typeof setTimeout> | null = null;
 let toastTimer: ReturnType<typeof setTimeout> | null = null;
 
+/** documentHidden reports whether the app is currently backgrounded. */
+function documentHidden(): boolean {
+  return typeof document !== 'undefined' && document.visibilityState === 'hidden';
+}
+
 export function showToast(text: string, kind: Toast['kind'] = 'info'): void {
   app.toast = { kind, text };
   if (toastTimer) clearTimeout(toastTimer);
@@ -70,6 +78,7 @@ export function handleError(err: unknown): void {
 
 function openStream(): void {
   closeStream();
+  streamAlive = true;
   unsubscribeStream = gateway.subscribe(
     (e) => {
       app.lastEvent = e;
@@ -85,10 +94,30 @@ function openStream(): void {
         void refreshNotifications();
       }
     },
-    () => showToast(t('error.unavailable'), 'error'),
+    () => {
+      streamAlive = false;
+      // A background suspend (iOS / Telegram) drops the single-shot stream. Don't
+      // alarm the user with the connection banner while hidden — reconnect silently
+      // on return (the visibilitychange handler). Show the banner only on a failure
+      // seen in the foreground, and retry it.
+      if (!documentHidden()) {
+        showToast(t('error.unavailable'), 'error');
+        scheduleReconnect();
+      }
+    },
   );
 }
 
+/** scheduleReconnect reopens a dropped stream once, after a short delay, while the
+ * app is in the foreground (a single pending attempt at a time). */
+function scheduleReconnect(): void {
+  if (reconnectTimer || !app.session) return;
+  reconnectTimer = setTimeout(() => {
+    reconnectTimer = null;
+    if (app.session && !streamAlive && !documentHidden()) openStream();
+  }, 4000);
+}
+
 /**
  * refreshNotifications recomputes the lobby badge count (incoming friend requests
  * plus open invitations). Authoritative poll, complementing the live 'notify' push.
@@ -111,8 +140,13 @@ export async function refreshNotifications(): Promise<void> {
 }
 
 function closeStream(): void {
+  if (reconnectTimer) {
+    clearTimeout(reconnectTimer);
+    reconnectTimer = null;
+  }
   unsubscribeStream?.();
   unsubscribeStream = null;
+  streamAlive = false;
 }
 
 async function adoptSession(s: Session): Promise<void> {
@@ -170,6 +204,10 @@ export async function bootstrap(): Promise<void> {
   if (insideTelegram()) {
     const launch = telegramLaunch();
     if (launch.theme) applyTelegramTheme(launch.theme);
+    // Inside Telegram the colour scheme is Telegram's to decide; force it explicitly
+    // so the OS prefers-color-scheme (which leaks into the Telegram Desktop webview)
+    // cannot fight it. Falls back to the stored preference when the SDK omits it.
+    applyTheme(telegramColorScheme() ?? app.theme);
     try {
       await adoptSession(await gateway.authTelegram(launch.initData));
       await routeStartParam(launch.startParam);
@@ -249,6 +287,7 @@ export async function loginEmail(email: string, code: string): Promise<void> {
 
 export async function logout(): Promise<void> {
   closeStream();
+  clearGameCache();
   gateway.setToken(null);
   await clearSession();
   app.session = null;
@@ -314,10 +353,14 @@ export function setBoardLabels(mode: BoardLabelMode): void {
   persistPrefs();
 }
 
-// Refresh the lobby badge when the app returns to the foreground — a push 'notify'
-// may have been missed while the client was hidden/closed (poll + push, see §10).
+// On return to the foreground: silently re-establish a stream dropped while the app
+// was backgrounded (iOS/Telegram suspend it), and refresh the lobby badge for any
+// push 'notify' missed while hidden (poll + push, see §10).
 if (typeof document !== 'undefined') {
   document.addEventListener('visibilitychange', () => {
-    if (document.visibilityState === 'visible' && app.session) void refreshNotifications();
+    if (document.visibilityState === 'visible' && app.session) {
+      if (!streamAlive) openStream();
+      void refreshNotifications();
+    }
   });
 }
diff --git a/ui/src/lib/gamecache.ts b/ui/src/lib/gamecache.ts
new file mode 100644
index 0000000..878d294
--- /dev/null
+++ b/ui/src/lib/gamecache.ts
@@ -0,0 +1,30 @@
+// In-memory per-game cache. A game the player has opened once is kept here so a
+// later re-entry renders instantly from the cache while a fresh fetch updates it in
+// the background — removing the blank "loading" flash and the full redraw on every
+// lobby <-> game navigation. It is intentionally process-memory only (no persistence):
+// stale entries are corrected by the background refresh, and the cache is cleared on
+// logout.
+
+import type { MoveRecord, StateView } from './model';
+
+interface CachedGame {
+  view: StateView;
+  moves: MoveRecord[];
+}
+
+const cache = new Map<string, CachedGame>();
+
+/** getCachedGame returns the last-seen state+history for a game, or undefined. */
+export function getCachedGame(id: string): CachedGame | undefined {
+  return cache.get(id);
+}
+
+/** setCachedGame stores the latest state+history for a game. */
+export function setCachedGame(id: string, view: StateView, moves: MoveRecord[]): void {
+  cache.set(id, { view, moves });
+}
+
+/** clearGameCache drops every cached game (called on logout). */
+export function clearGameCache(): void {
+  cache.clear();
+}
diff --git a/ui/src/lib/mock/alphabet.ts b/ui/src/lib/mock/alphabet.ts
index 365d4bf..b097558 100644
--- a/ui/src/lib/mock/alphabet.ts
+++ b/ui/src/lib/mock/alphabet.ts
@@ -12,7 +12,7 @@ import type { Variant } from '../model';
 const SPECS: Record<Variant, string> = {
   english:
     'a1 b3 c3 d2 e1 f4 g2 h4 i1 j8 k5 l1 m3 n1 o1 p3 q10 r1 s1 t1 u1 v4 w4 x8 y4 z10',
-  russian:
+  russian_scrabble:
     'а1 б3 в1 г3 д2 е1 ё3 ж5 з5 и1 й4 к2 л2 м2 н1 о1 п2 р1 с1 т1 у2 ф10 х5 ц5 ч5 ш8 щ10 ъ10 ы4 ь3 э8 ю8 я3',
   erudit:
     'а1 б3 в2 г3 д2 е1 ё0 ж5 з5 и1 й2 к2 л2 м2 н1 о1 п2 р2 с2 т2 у3 ф10 х5 ц10 ч5 ш10 щ10 ъ10 ы5 ь5 э10 ю10 я3',
diff --git a/ui/src/lib/mock/client.ts b/ui/src/lib/mock/client.ts
index 4de876f..ef4a1c7 100644
--- a/ui/src/lib/mock/client.ts
+++ b/ui/src/lib/mock/client.ts
@@ -62,7 +62,7 @@ function emptyLinked(): LinkResult {
 
 const POOL: Record<Variant, string> = {
   english: 'AAAAEEEEIIIOONNRRTTLLSSUDGBCMPFHVWYK',
-  russian: 'ОООААЕЕИИННТТСРРВЛКМДПУЯЫЬГЗБ',
+  russian_scrabble: 'ОООААЕЕИИННТТСРРВЛКМДПУЯЫЬГЗБ',
   erudit: 'ОООААЕЕИИННТТСРРВЛКМДПУЯЫЬГЗБ',
 };
 
diff --git a/ui/src/lib/mock/data.ts b/ui/src/lib/mock/data.ts
index c0d0522..d9ab895 100644
--- a/ui/src/lib/mock/data.ts
+++ b/ui/src/lib/mock/data.ts
@@ -203,7 +203,7 @@ function finishedG3(): MockGame {
   return {
     view: {
       id: 'g3',
-      variant: 'russian',
+      variant: 'russian_scrabble',
       dictVersion: 'v1',
       status: 'finished',
       players: 2,
diff --git a/ui/src/lib/model.ts b/ui/src/lib/model.ts
index aa7ad1c..318a2d2 100644
--- a/ui/src/lib/model.ts
+++ b/ui/src/lib/model.ts
@@ -3,7 +3,7 @@
 // FlatBuffers) and the mock transport speak this model, so the UI never touches
 // generated wire code directly.
 
-export type Variant = 'english' | 'russian' | 'erudit';
+export type Variant = 'english' | 'russian_scrabble' | 'erudit';
 
 /** Backend game status strings. */
 export type GameStatus = 'active' | 'finished' | string;
diff --git a/ui/src/lib/premiums.test.ts b/ui/src/lib/premiums.test.ts
index 1279d1e..a24490d 100644
--- a/ui/src/lib/premiums.test.ts
+++ b/ui/src/lib/premiums.test.ts
@@ -23,7 +23,7 @@ describe('premium layout', () => {
   it('doubles the centre for standard variants but not for erudit', () => {
     expect(centre('english')).toEqual({ row: 7, col: 7 });
     expect(premiumGrid('english')[7][7]).toBe('DW');
-    expect(premiumGrid('russian')[7][7]).toBe('DW');
+    expect(premiumGrid('russian_scrabble')[7][7]).toBe('DW');
     expect(centre('erudit')).toEqual({ row: 7, col: 7 });
     expect(premiumGrid('erudit')[7][7]).toBe('');
   });
diff --git a/ui/src/lib/telegram.ts b/ui/src/lib/telegram.ts
index db77efd..da5455d 100644
--- a/ui/src/lib/telegram.ts
+++ b/ui/src/lib/telegram.ts
@@ -9,6 +9,7 @@ interface TelegramWebApp {
   initData: string;
   initDataUnsafe?: { start_param?: string };
   themeParams?: TelegramThemeParams;
+  colorScheme?: 'light' | 'dark';
   ready?: () => void;
   expand?: () => void;
 }
@@ -48,6 +49,17 @@ export function telegramLaunch(): TelegramLaunch {
   return { initData: w.initData, startParam, theme: w.themeParams };
 }
 
+/**
+ * telegramColorScheme returns Telegram's active colour scheme ('light' | 'dark'),
+ * or undefined outside Telegram. Inside the Mini App this — not the OS
+ * prefers-color-scheme — is the authoritative theme: on some clients (Telegram
+ * Desktop) the OS scheme leaks into the webview and fights Telegram's own setting,
+ * so the app forces this value on launch.
+ */
+export function telegramColorScheme(): 'light' | 'dark' | undefined {
+  return webApp()?.colorScheme;
+}
+
 /**
  * startParamFromURL reads a startapp parameter from the page URL — a bot web_app
  * launch button carries the deep-link there rather than in initDataUnsafe.
diff --git a/ui/src/lib/theme.ts b/ui/src/lib/theme.ts
index 080f6e0..d4c0214 100644
--- a/ui/src/lib/theme.ts
+++ b/ui/src/lib/theme.ts
@@ -27,6 +27,7 @@ export interface TelegramThemeParams {
   button_color?: string;
   button_text_color?: string;
   secondary_bg_color?: string;
+  header_bg_color?: string;
 }
 
 /** applyTelegramTheme overrides token values at runtime from Telegram themeParams. */
@@ -44,4 +45,8 @@ export function applyTelegramTheme(p: TelegramThemeParams): void {
   set(p.button_color, '--accent');
   set(p.button_text_color, '--accent-text');
   set(p.link_color, '--accent');
+  // The nav bar tracks Telegram's chrome so it doesn't fall out of the design; the
+  // announcement banner takes the secondary surface so it reads as a subtle accent.
+  set(p.header_bg_color ?? p.bg_color, '--bg-elev');
+  set(p.secondary_bg_color, '--ad-bg');
 }
diff --git a/ui/src/lib/variants.test.ts b/ui/src/lib/variants.test.ts
index cb87252..cb80b1e 100644
--- a/ui/src/lib/variants.test.ts
+++ b/ui/src/lib/variants.test.ts
@@ -13,10 +13,10 @@ describe('availableVariants', () => {
   });
 
   it('offers Russian and Эрудит for a ru-only service', () => {
-    expect(availableVariants(['ru']).map((v) => v.id)).toEqual(['russian', 'erudit']);
+    expect(availableVariants(['ru']).map((v) => v.id)).toEqual(['russian_scrabble', 'erudit']);
   });
 
   it('offers every variant for a bilingual service', () => {
-    expect(availableVariants(['en', 'ru']).map((v) => v.id)).toEqual(['english', 'russian', 'erudit']);
+    expect(availableVariants(['en', 'ru']).map((v) => v.id)).toEqual(['english', 'russian_scrabble', 'erudit']);
   });
 });
diff --git a/ui/src/lib/variants.ts b/ui/src/lib/variants.ts
index db20b60..31ad921 100644
--- a/ui/src/lib/variants.ts
+++ b/ui/src/lib/variants.ts
@@ -14,13 +14,13 @@ export interface VariantOption {
 // ALL_VARIANTS lists every variant in display order.
 export const ALL_VARIANTS: VariantOption[] = [
   { id: 'english', label: 'new.english' },
-  { id: 'russian', label: 'new.russian' },
+  { id: 'russian_scrabble', label: 'new.russian' },
   { id: 'erudit', label: 'new.erudit' },
 ];
 
 // VARIANT_LANGUAGE maps each variant to its game language. en -> English;
 // ru -> Russian + Эрудит.
-export const VARIANT_LANGUAGE: Record<Variant, 'en' | 'ru'> = { english: 'en', russian: 'ru', erudit: 'ru' };
+export const VARIANT_LANGUAGE: Record<Variant, 'en' | 'ru'> = { english: 'en', russian_scrabble: 'ru', erudit: 'ru' };
 
 // availableVariants gates ALL_VARIANTS by the session's supported languages. An empty
 // or absent set is ungated (a web/legacy session without a declared set), returning
diff --git a/ui/src/screens/Lobby.svelte b/ui/src/screens/Lobby.svelte
index ad0513a..685a983 100644
--- a/ui/src/screens/Lobby.svelte
+++ b/ui/src/screens/Lobby.svelte
@@ -78,7 +78,7 @@
 
   const variantKey: Record<string, MessageKey> = {
     english: 'new.english',
-    russian: 'new.russian',
+    russian_scrabble: 'new.russian',
     erudit: 'new.erudit',
   };
 </script>
diff --git a/ui/src/screens/Settings.svelte b/ui/src/screens/Settings.svelte
index 2ca4360..b2cfc53 100644
--- a/ui/src/screens/Settings.svelte
+++ b/ui/src/screens/Settings.svelte
@@ -10,6 +10,7 @@
   import { t, type Locale, type MessageKey } from '../lib/i18n/index.svelte';
   import type { ThemePref } from '../lib/theme';
   import type { BoardLabelMode } from '../lib/boardlabels';
+  import { insideTelegram } from '../lib/telegram';
 
   const themes: ThemePref[] = ['auto', 'light', 'dark'];
   const themeLabel: Record<ThemePref, MessageKey> = {
@@ -28,16 +29,18 @@
 
 <Screen title={t('settings.title')} back="/">
   <div class="page">
-    <section>
-      <h3>{t('settings.theme')}</h3>
-      <div class="seg">
-        {#each themes as th (th)}
-          <button class="opt" class:active={app.theme === th} onclick={() => setTheme(th)}>
-            {t(themeLabel[th])}
-          </button>
-        {/each}
-      </div>
-    </section>
+    {#if !insideTelegram()}
+      <section>
+        <h3>{t('settings.theme')}</h3>
+        <div class="seg">
+          {#each themes as th (th)}
+            <button class="opt" class:active={app.theme === th} onclick={() => setTheme(th)}>
+              {t(themeLabel[th])}
+            </button>
+          {/each}
+        </div>
+      </section>
+    {/if}
 
     <section>
       <h3>{t('settings.language')}</h3>