feat(frontend): standalone theme-picker modal, offline anti-repeat, dimmer opponent green

- Solo theme choice moves out of the settings menu into its own
  post-Play modal; Play Again reopens it for chosen-theme rounds and
  instantly rerolls (never repeating the last theme) for random rounds.
- Last solo/bot theme played persists in localStorage so a fresh
  random pick or page reload doesn't immediately repeat it.
- Result modal swaps Change Theme for a Back to Menu button for as
  long as a solo/bot round is active.
- Darkened the opponent-progress fill color (renderer.ts).

frontend/index.html

@@ -105,11 +105,6 @@
             </div>
           </div>
 
-          <div id="solo-theme-picker" class="hidden">
-            <p class="pick-theme-label">▼ PICK A THEME ▼</p>
-            <div id="theme-grid" class="theme-grid"></div>
-          </div>
-
           <div class="solo-config-group">
             <p class="solo-config-label">🤖 OPPONENT</p>
             <div class="solo-radio-row">
@@ -190,11 +185,22 @@
       <div class="modal-actions">
         <button id="close-result-btn" class="btn ghost">Keep Comparing</button>
         <button id="change-theme-btn" class="btn ghost">🔄 Change Theme</button>
+        <button id="back-to-menu-btn" class="btn ghost hidden">🏠 Back to Menu</button>
         <button id="play-again-btn" class="btn primary">Play Again</button>
       </div>
     </div>
   </div>
 
+  <div id="theme-picker-modal" class="modal-overlay hidden">
+    <div class="modal">
+      <h2>🎨 CHOOSE A THEME</h2>
+      <div id="theme-picker-grid" class="theme-grid"></div>
+      <div class="modal-actions">
+        <button id="theme-picker-cancel-btn" class="btn ghost">Cancel</button>
+      </div>
+    </div>
+  </div>
+
   <div id="preview-overlay" class="modal-overlay hidden">
     <div class="preview-box">
       <div class="preview-countdown" id="preview-countdown">5</div>

frontend/src/game/renderer.ts

@@ -70,7 +70,7 @@ export function drawFrame(state: RenderState, now: number): void {
  * actual color is never transmitted or known here (see PROTOCOL.md
  * `round:progress`), so this is the only color this view can ever show
  * for a picked category. */
-export const OPPONENT_ASSIGNED_HEX = '#5fd75f';
+export const OPPONENT_ASSIGNED_HEX = '#3e8c3e';
 /** Flat grey used for categories the opponent hasn't picked yet. */
 export const OPPONENT_UNASSIGNED_HEX = '#3a3a52';
 

frontend/src/main.ts

@@ -1,6 +1,5 @@
 import './style.css';
 import { sound } from './engine/sound';
-import { createThemeGrid } from './ui/themeGrid';
 import { createSoloConfigFlow } from './ui/soloConfigFlow';
 import { createMatchmakingFlow } from './ui/matchmakingFlow';
 import { createPrivateRoomFlow } from './ui/privateRoomFlow';
@@ -14,9 +13,7 @@ function requireEl<T extends HTMLElement>(id: string): T {
 
 const menuModal = requireEl<HTMLElement>('intro-modal');
 const resultModal = requireEl<HTMLElement>('result-modal');
-const themeGridEl = requireEl<HTMLElement>('theme-grid');
 const menuSoloSection = requireEl<HTMLElement>('menu-solo');
-const soloThemePickerWrap = requireEl<HTMLElement>('solo-theme-picker');
 const soloBotDifficultyWrap = requireEl<HTMLElement>('solo-bot-difficulty');
 const soloTimerMount = requireEl<HTMLElement>('solo-timer-mount');
 const startBtn = requireEl<HTMLButtonElement>('start-btn');
@@ -28,6 +25,7 @@ const helpBtn = requireEl<HTMLButtonElement>('help-btn');
 const muteBtn = requireEl<HTMLButtonElement>('mute-btn');
 const themeNameBadge = requireEl<HTMLElement>('theme-name-badge');
 const changeThemeBtn = requireEl<HTMLButtonElement>('change-theme-btn');
+const backToMenuBtn = requireEl<HTMLButtonElement>('back-to-menu-btn');
 const privateRoomMount = requireEl<HTMLElement>('private-room-mount');
 
 const previewElements = {
@@ -37,6 +35,12 @@ const previewElements = {
   canvas: requireEl<HTMLCanvasElement>('preview-canvas'),
 };
 
+const themePickerElements = {
+  overlay: requireEl<HTMLElement>('theme-picker-modal'),
+  gridMount: requireEl<HTMLElement>('theme-picker-grid'),
+  cancelBtn: requireEl<HTMLButtonElement>('theme-picker-cancel-btn'),
+};
+
 /** Top-level overlay screens the composition root switches between. At most
  * one is visible at a time; the game board underneath is always present and
  * simply gets obscured while a screen is shown. */
@@ -53,19 +57,18 @@ function showView(name: ScreenName | null): void {
   }
 }
 
-const themeGrid = createThemeGrid(themeGridEl, 'gruvbox', () => sound.playOpen());
-
 createSoloConfigFlow(
   {
     section: menuSoloSection,
-    themePickerWrap: soloThemePickerWrap,
     botDifficultyWrap: soloBotDifficultyWrap,
     playBtn: startBtn,
     timerMount: soloTimerMount,
     themeNameBadge,
     preview: previewElements,
+    themePicker: themePickerElements,
+    changeThemeBtn,
+    backToMenuBtn,
   },
-  themeGrid,
   { hideMenu: () => showView(null), showMenu: () => showView('menu') },
 );
 

frontend/src/style.css

@@ -482,13 +482,6 @@ body {
 }
 .modal ol { padding-left: 20px; line-height: 1.7; color: var(--fg-dim); font-size: 13px; }
 .modal p { color: var(--fg-dim); font-size: 13px; }
-.pick-theme-label {
-  font-family: var(--pixel);
-  font-size: 9px;
-  color: var(--cyan);
-  text-align: center;
-  margin: 18px 0 10px;
-}
 
 .theme-grid {
   display: grid;
@@ -592,8 +585,6 @@ body {
   animation: revealPulse 1.6s steps(2) infinite;
 }
 
-#menu-solo .theme-grid { margin-bottom: 0; }
-
 .solo-config-group { display: flex; flex-direction: column; gap: 6px; }
 .solo-config-label { margin: 0; font-family: var(--pixel); font-size: 9px; color: var(--fg-dim); letter-spacing: .5px; }
 .solo-radio-row { display: flex; gap: 6px; flex-wrap: wrap; }
@@ -613,7 +604,7 @@ body {
 .solo-radio:has(input:checked) { background: var(--panel-3); color: var(--fg); border-color: var(--yellow); }
 .solo-radio input { accent-color: var(--yellow); margin: 0; }
 
-#solo-theme-picker.hidden, #solo-bot-difficulty.hidden { display: none; }
+#solo-bot-difficulty.hidden { display: none; }
 
 @media (max-width: 640px) {
   .menu-sections { grid-template-columns: 1fr; }

frontend/src/ui/soloConfigFlow.ts

@@ -8,7 +8,7 @@ import type { ThemeGuessGame } from '../game/ThemeGuessGame';
 import type { ThemeId } from '../types';
 import type { PreviewFlowElements } from './previewFlow';
 import { runThemePreview } from './previewFlow';
-import type { ThemeGrid } from './themeGrid';
+import { createThemeGrid } from './themeGrid';
 
 /** Reuses `engine/bot`'s time-mode vocabulary so a solo config can be
  * handed straight to `computeBotSchedule` once the bot opponent path
@@ -26,13 +26,16 @@ export interface SoloConfig {
   botDifficulty: BotDifficulty;
 }
 
+/** Everything a round needs except the theme itself — resolved from the
+ * menu form (or carried over from `lastConfig` on "Play Again") before
+ * the theme-picker modal supplies the last piece. */
+type PendingSoloConfig = Omit<SoloConfig, 'themeId' | 'snippetIndex'>;
+
 export interface SoloConfigFlowElements {
   /** Root of the #menu-solo section; radios are looked up inside it by
    * `name` so this module owns its own markup instead of main.ts wiring
    * every individual input. */
   section: HTMLElement;
-  /** Wrapper around the reused theme grid, shown only in "choose" mode. */
-  themePickerWrap: HTMLElement;
   /** Wrapper around the difficulty radios, shown only in "vs bot" mode. */
   botDifficultyWrap: HTMLElement;
   playBtn: HTMLButtonElement;
@@ -43,6 +46,19 @@ export interface SoloConfigFlowElements {
   themeNameBadge: HTMLElement;
   /** Mounts for the pre-round "flash the real theme" overlay. */
   preview: PreviewFlowElements;
+  /** Standalone "pick a theme" modal shown after Play or Play Again in
+   * chosen-theme mode — never inline in the settings menu. */
+  themePicker: {
+    overlay: HTMLElement;
+    gridMount: HTMLElement;
+    cancelBtn: HTMLButtonElement;
+  };
+  /** Result-modal button used by every non-solo match; hidden for as
+   * long as a solo/bot round is active, in favor of `backToMenuBtn`. */
+  changeThemeBtn: HTMLButtonElement;
+  /** Result-modal button shown in `changeThemeBtn`'s place once a
+   * solo/bot round has started. */
+  backToMenuBtn: HTMLButtonElement;
 }
 
 export interface SoloConfigFlowHooks {
@@ -85,6 +101,43 @@ function checkedValue<T extends string>(inputs: HTMLInputElement[], fallback: T)
   return (inputs.find((input) => input.checked)?.value as T | undefined) ?? fallback;
 }
 
+/** Offline (solo/bot) anti-repeat memory: the last theme actually
+ * played, persisted so a page reload doesn't immediately re-serve it.
+ * Multiplayer theme selection (server-assigned or voted) never touches
+ * this key. */
+const LAST_THEME_STORAGE_KEY = 'theme-guess:last-solo-theme';
+
+function isThemeId(value: string): value is ThemeId {
+  return value in THEMES;
+}
+
+function readLastTheme(): ThemeId | null {
+  try {
+    const stored = window.localStorage.getItem(LAST_THEME_STORAGE_KEY);
+    return stored && isThemeId(stored) ? stored : null;
+  } catch {
+    return null;
+  }
+}
+
+function writeLastTheme(themeId: ThemeId): void {
+  try {
+    window.localStorage.setItem(LAST_THEME_STORAGE_KEY, themeId);
+  } catch {
+    // Storage unavailable (private browsing, disabled) — anti-repeat
+    // just resets every page load instead of persisting across them.
+  }
+}
+
+/** Picks a random theme other than `exclude`, falling back to the full
+ * pool if excluding it would leave nothing to pick from. */
+function pickRandomTheme(exclude: ThemeId | null): ThemeId {
+  const ids = Object.keys(THEMES) as ThemeId[];
+  const pool = exclude ? ids.filter((id) => id !== exclude) : ids;
+  const candidates = pool.length > 0 ? pool : ids;
+  return candidates[Math.floor(Math.random() * candidates.length)];
+}
+
 interface TimerHud {
   /** Starts (or restarts) the countdown/elapsed-time display. `onExpire`,
    * on the two clocked modes only, fires exactly once when the countdown
@@ -154,13 +207,13 @@ function createTimerHud(mount: HTMLElement, onQuit: () => void): TimerHud {
 }
 
 /** Wires the Solo menu section's config form (time mode / theme mode /
- * opponent, with the theme grid and bot difficulty picker revealed
+ * opponent, with the bot difficulty picker revealed conditionally and
- * conditionally), its inline timer/quit HUD, and every shared
+ * theme choice deferred to a standalone modal), its inline timer/quit
- * result-modal button ("Keep Comparing" / "Play Again") for as long as a
+ * HUD, and every shared result-modal button ("Keep Comparing" / "Play
- * solo round is the thing driving the shared board — see `soloActive`. */
+ * Again" / the change-theme/back-to-menu swap) for as long as a solo
+ * round is the thing driving the shared board — see `soloActive`. */
 export function createSoloConfigFlow(
   elements: SoloConfigFlowElements,
-  themeGrid: ThemeGrid,
   hooks: SoloConfigFlowHooks,
 ): void {
   const themeModeInputs = radios(elements.section, 'solo-theme-mode');
@@ -173,6 +226,10 @@ export function createSoloConfigFlow(
 
   let lastConfig: SoloConfig | null = null;
   let activeGame: ThemeGuessGame | null = null;
+  /** The non-theme settings a theme-picker-modal selection will complete
+   * into a full round — set whenever the modal opens, cleared once it's
+   * dismissed (by pick or Cancel). */
+  let pendingConfig: PendingSoloConfig | null = null;
   /** True from the moment a solo round starts until the player quits —
    * guards the shared, page-global result-modal buttons and the Quit
    * button so a stale click from a leftover matchmaking/private-room
@@ -181,19 +238,36 @@ export function createSoloConfigFlow(
 
   const timerHud = createTimerHud(elements.timerMount, quit);
 
-  function syncThemePicker(): void {
+  const themeGrid = createThemeGrid(elements.themePicker.gridMount, readLastTheme() ?? 'gruvbox', (themeId) => {
-    const mode = checkedValue<SoloThemeMode>(themeModeInputs, 'random');
+    sound.playOpen();
-    elements.themePickerWrap.classList.toggle('hidden', mode !== 'choose');
+    if (!pendingConfig) return;
+    const config = pendingConfig;
+    closeThemePicker();
+    beginRound({ ...config, themeId, snippetIndex: pickRandomSnippetIndex() });
+  });
+  void themeGrid;
+
+  function openThemePicker(config: PendingSoloConfig): void {
+    pendingConfig = config;
+    elements.themePicker.overlay.classList.remove('hidden');
   }
 
+  function closeThemePicker(): void {
+    pendingConfig = null;
+    elements.themePicker.overlay.classList.add('hidden');
+  }
+
+  elements.themePicker.cancelBtn.addEventListener('click', () => {
+    closeThemePicker();
+    hooks.showMenu();
+  });
+
   function syncBotDifficulty(): void {
     const opponent = checkedValue<SoloOpponent>(opponentInputs, 'alone');
     elements.botDifficultyWrap.classList.toggle('hidden', opponent !== 'bot');
   }
 
-  for (const input of themeModeInputs) input.addEventListener('change', syncThemePicker);
   for (const input of opponentInputs) input.addEventListener('change', syncBotDifficulty);
-  syncThemePicker();
   syncBotDifficulty();
 
   /** Starts (or restarts) a live round from a fully-resolved config:
@@ -202,6 +276,9 @@ export function createSoloConfigFlow(
   function beginRound(config: SoloConfig): void {
     lastConfig = config;
     soloActive = true;
+    writeLastTheme(config.themeId);
+    elements.changeThemeBtn.classList.add('hidden');
+    elements.backToMenuBtn.classList.remove('hidden');
     hooks.hideMenu();
     runThemePreview(elements.preview, config.themeId, () => {
       const game = getSharedGame(config.themeId, config.snippetIndex, (id, hex) => botMatch.handleLocalAssignment(id, hex));
@@ -235,20 +312,15 @@ export function createSoloConfigFlow(
     const themeMode = checkedValue<SoloThemeMode>(themeModeInputs, 'random');
     const opponent = checkedValue<SoloOpponent>(opponentInputs, 'alone');
     const botDifficulty = checkedValue<BotDifficulty>(botDifficultyInputs, 'easy');
+    const base: PendingSoloConfig = { timeMode, themeMode, opponent, botDifficulty };
 
-    const themeIds = Object.keys(THEMES) as ThemeId[];
+    if (themeMode === 'choose') {
-    const themeId = themeMode === 'choose'
+      hooks.hideMenu();
-      ? themeGrid.selected
+      openThemePicker(base);
-      : themeIds[Math.floor(Math.random() * themeIds.length)];
+      return;
+    }
 
-    beginRound({
+    beginRound({ ...base, themeId: pickRandomTheme(readLastTheme()), snippetIndex: pickRandomSnippetIndex() });
-      themeId,
-      snippetIndex: pickRandomSnippetIndex(),
-      timeMode,
-      themeMode,
-      opponent,
-      botDifficulty,
-    });
   });
 
   /** "Keep Comparing": lets the player keep tweaking colors after a
@@ -264,32 +336,41 @@ export function createSoloConfigFlow(
   }
 
   /** "Play Again": a random-theme round immediately rerolls a new theme
-   * and snippet and starts over, with no extra input needed. A
+   * (never repeating the last one played) and snippet, and starts over
-   * chosen-theme round instead reopens the menu (already sitting on
+   * with no extra input needed. A chosen-theme round instead reopens the
-   * "choose" with the theme grid visible) so the player picks their
+   * standalone theme-picker modal, carrying over every other setting, so
-   * next theme, same as starting any other chosen-theme round. */
+   * the player picks their next theme the same way a fresh round does. */
   function playAgain(): void {
     if (!soloActive || !lastConfig) return;
+    const base: PendingSoloConfig = {
+      timeMode: lastConfig.timeMode,
+      themeMode: lastConfig.themeMode,
+      opponent: lastConfig.opponent,
+      botDifficulty: lastConfig.botDifficulty,
+    };
+
     if (lastConfig.themeMode === 'choose') {
-      hooks.showMenu();
+      openThemePicker(base);
       return;
     }
-    const themeIds = Object.keys(THEMES) as ThemeId[];
+
-    const themeId = themeIds[Math.floor(Math.random() * themeIds.length)];
+    beginRound({ ...base, themeId: pickRandomTheme(readLastTheme()), snippetIndex: pickRandomSnippetIndex() });
-    beginRound({ ...lastConfig, themeId, snippetIndex: pickRandomSnippetIndex() });
   }
 
   /** Ends the active solo round and returns to the main menu — wired to
-   * the timer HUD's own Quit button, which is visible for as long as a
+   * the timer HUD's own Quit button (visible for as long as a solo round
-   * solo round is live (menu, mid-round, and after a reveal alike). */
+   * is live) and the result modal's "Back to Menu" button. */
   function quit(): void {
     if (!soloActive) return;
     soloActive = false;
     botMatch.stop();
     timerHud.hide();
+    elements.changeThemeBtn.classList.remove('hidden');
+    elements.backToMenuBtn.classList.add('hidden');
     hooks.showMenu();
   }
 
+  elements.backToMenuBtn.addEventListener('click', quit);
   closeResultBtn.addEventListener('click', keepComparing);
   playAgainBtn.addEventListener('click', playAgain);
 }