feat(audio): Haus ambient sounds + YouTube player fix

WhiteNoise replaced with full ambient mixer:
- 6 categories: Noise, Rain, Nature, Places, Things, Animals
- 29 real ambient sounds from Haus (MIT licensed)
- Howler.js for playback with looping and per-sound volume
- Mix multiple sounds simultaneously
- Category tab navigation
- 300ms fade in/out for smooth toggling

MusicPlayer fixes:
- Removed origin param (causes issues behind reverse proxy)
- Added onError handler for YouTube errors
- Added onStateChange to track playing state
- Player container 1x1 opacity:0 instead of offscreen positioning

frontend/package-lock.json

@@ -8,6 +8,7 @@
       "name": "kira",
       "version": "0.1.0",
       "dependencies": {
+        "howler": "^2.2.4",
         "pixi-live2d-display": "^0.4.0",
         "pixi.js": "^7.4.3",
         "react": "^19.2.6",
@@ -15,13 +16,14 @@
       },
       "devDependencies": {
         "@tailwindcss/vite": "^4.1.6",
+        "@types/howler": "^2.2.13",
         "@types/react": "^19.2.14",
         "@types/react-dom": "^19.2.3",
         "@vitejs/plugin-react": "^6.0.1",
         "autoprefixer": "^10.4.20",
         "postcss": "^8.5.3",
         "tailwindcss": "^4.1.6",
-        "typescript": "~6.0.2",
+        "typescript": "^6.0.3",
         "vite": "^8.0.12"
       }
     },
@@ -871,6 +873,13 @@
       "integrity": "sha512-qp3m9PPz4gULB9MhjGID7wpo3gJ4bTGXm7ltNDsmOvsPduTeHp8wSW9YckBj3mljeOh4F0m2z/0JKAALRKbmLQ==",
       "license": "MIT"
     },
+    "node_modules/@types/howler": {
+      "version": "2.2.13",
+      "resolved": "https://registry.npmjs.org/@types/howler/-/howler-2.2.13.tgz",
+      "integrity": "sha512-40+EBjqIHHrC4VShlz/7i0lBUsE3QkgzZinQQji74Hd8sBkJZUBaT7LWFLK6rcabsDOOQpoMbEJvtaFQwxOu/g==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/@types/offscreencanvas": {
       "version": "2019.7.3",
       "resolved": "https://registry.npmjs.org/@types/offscreencanvas/-/offscreencanvas-2019.7.3.tgz",
@@ -998,9 +1007,9 @@
       "license": "MIT"
     },
     "node_modules/baseline-browser-mapping": {
-      "version": "2.10.33",
-      "resolved": "https://registry.npmjs.org/baseline-browser-mapping/-/baseline-browser-mapping-2.10.33.tgz",
-      "integrity": "sha512-bA6+tcSLpz2tIEdDXZPpPTIuxBcC4+w6SieaYyfigIa4h8GlFxbA17v22Vx3JUtuZQj9SgOsnbK+aTBzyDyEuw==",
+      "version": "2.10.34",
+      "resolved": "https://registry.npmjs.org/baseline-browser-mapping/-/baseline-browser-mapping-2.10.34.tgz",
+      "integrity": "sha512-IMDedajPifLnHNY0X9n8hKxRTQ6/eTHwr5bDo04WnuqxyKw6LYtQywCuuqPZwhl3aBXMvQpJov42GLCwRRdQzw==",
       "dev": true,
       "license": "Apache-2.0",
       "bin": {
@@ -1160,9 +1169,9 @@
       "license": "ISC"
     },
     "node_modules/electron-to-chromium": {
-      "version": "1.5.367",
-      "resolved": "https://registry.npmjs.org/electron-to-chromium/-/electron-to-chromium-1.5.367.tgz",
-      "integrity": "sha512-4Mk/mrynCNQ+atY40D3UpmhLWB6AHMbYMlIrPhHcMF6x0L7O0b052FCAsxw1LlaR++UFuNg3D/A6XCuGDa0guQ==",
+      "version": "1.5.368",
+      "resolved": "https://registry.npmjs.org/electron-to-chromium/-/electron-to-chromium-1.5.368.tgz",
+      "integrity": "sha512-7RckJJK4uESJF9PxvfMWd3TGqIiieUTG4HxnKaKuIpGbcr+r2ZEB3g2gAhCP3Fqm42vJSzLfgab9eva/C4/XVw==",
       "dev": true,
       "license": "ISC"
     },
@@ -1173,9 +1182,9 @@
       "license": "MIT"
     },
     "node_modules/enhanced-resolve": {
-      "version": "5.22.2",
-      "resolved": "https://registry.npmjs.org/enhanced-resolve/-/enhanced-resolve-5.22.2.tgz",
-      "integrity": "sha512-0rxICaFZ7NQho/sHely2bvOPRP0Eu2B0NZ9zM54YvRvWMn7jfz3DmnOZDR9LlXDdDcqntAVc6Hfy4gr/tdH/Ag==",
+      "version": "5.23.0",
+      "resolved": "https://registry.npmjs.org/enhanced-resolve/-/enhanced-resolve-5.23.0.tgz",
+      "integrity": "sha512-yJN/BOOLxcOW2aQgeif9mSnaUB8KtvmMMp56oA1kx1CRfBKbhZm2pJ+NBY+3eOboHxix8lfjWpHE0Ei5U8RbSA==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
@@ -1512,6 +1521,12 @@
         "node": ">= 0.4"
       }
     },
+    "node_modules/howler": {
+      "version": "2.2.4",
+      "resolved": "https://registry.npmjs.org/howler/-/howler-2.2.4.tgz",
+      "integrity": "sha512-iARIBPgcQrwtEr+tALF+rapJ8qSc+Set2GJQl7xT1MQzWaVkFebdJhR3alVlSiUf5U7nAANKuj3aWpwerocD5w==",
+      "license": "MIT"
+    },
     "node_modules/inflight": {
       "version": "1.0.6",
       "resolved": "https://registry.npmjs.org/inflight/-/inflight-1.0.6.tgz",

frontend/package.json

@@ -9,6 +9,7 @@
     "preview": "vite preview"
   },
   "dependencies": {
+    "howler": "^2.2.4",
     "pixi-live2d-display": "^0.4.0",
     "pixi.js": "^7.4.3",
     "react": "^19.2.6",
@@ -16,13 +17,14 @@
   },
   "devDependencies": {
     "@tailwindcss/vite": "^4.1.6",
+    "@types/howler": "^2.2.13",
     "@types/react": "^19.2.14",
     "@types/react-dom": "^19.2.3",
     "@vitejs/plugin-react": "^6.0.1",
     "autoprefixer": "^10.4.20",
     "postcss": "^8.5.3",
     "tailwindcss": "^4.1.6",
-    "typescript": "~6.0.2",
+    "typescript": "^6.0.3",
     "vite": "^8.0.12"
   }
 }

frontend/src/components/MusicPlayer.tsx

@@ -17,38 +17,21 @@ export default function MusicPlayer() {
   const [activeId, setActiveId] = useState<string>('lofi-girl');
   const [volume, setVolume] = useState(0.3);
   const [started, setStarted] = useState(false);
-  const [playerReady, setPlayerReady] = useState(false);
+  const [playing, setPlaying] = useState(false);
   const playerRef = useRef<any>(null);
   const volumeRef = useRef(volume);
   const activeIdRef = useRef(activeId);
+  const readyResolveRef = useRef<(() => void) | null>(null);
 
-  // Keep refs in sync so the API callback sees current values
   useEffect(() => { volumeRef.current = volume; }, [volume]);
   useEffect(() => { activeIdRef.current = activeId; }, [activeId]);
 
-  // Load YouTube IFrame API
-  const loadAPI = useCallback(() => {
-    if (document.querySelector('script[src="https://www.youtube.com/iframe_api"]')) {
-      // Already loaded — just wait for YT to be ready
-      if ((window as any).YT?.Player) {
-        createPlayer();
-      }
-      return;
-    }
-
-    const tag = document.createElement('script');
-    tag.src = 'https://www.youtube.com/iframe_api';
-    document.head.appendChild(tag);
-
-    (window as any).onYouTubeIframeAPIReady = () => {
-      createPlayer();
-    };
-  }, []);
-
-  const createPlayer = useCallback(() => {
+  // Load YouTube IFrame API and create player
+  const initPlayer = useCallback(() => {
     const active = LOFI_PLAYLISTS.find((p) => p.id === activeIdRef.current);
     if (!active || playerRef.current) return;
 
+    const createYT = () => {
       playerRef.current = new (window as any).YT.Player('kira-youtube-player', {
         height: '1',
         width: '1',
@@ -59,43 +42,64 @@ export default function MusicPlayer() {
           loop: 1,
           playlist: active.videoId,
           enablejsapi: 1,
-        origin: window.location.origin,
           modestbranding: 1,
           fs: 0,
+          rel: 0,
         },
         events: {
           onReady: (e: any) => {
             e.target.setVolume(Math.round(volumeRef.current * 100));
             e.target.playVideo();
-          setPlayerReady(true);
+            setPlaying(true);
+          },
+          onStateChange: (e: any) => {
+            // YT.PlayerState.PLAYING = 1, PAUSED = 2, ENDED = 0
+            setPlaying(e.data === 1);
+          },
+          onError: (e: any) => {
+            console.warn('[MusicPlayer] YouTube error:', e.data);
           },
         },
       });
+    };
+
+    if ((window as any).YT?.Player) {
+      createYT();
+    } else {
+      // Load the script
+      const tag = document.createElement('script');
+      tag.src = 'https://www.youtube.com/iframe_api';
+      document.head.appendChild(tag);
+      (window as any).onYouTubeIframeAPIReady = createYT;
+    }
   }, []);
 
   const handlePlay = () => {
     setStarted(true);
-    loadAPI();
+    initPlayer();
   };
 
   const changeStation = (id: string) => {
     setActiveId(id);
-    if (playerRef.current && playerReady) {
+    if (playerRef.current && (window as any).YT) {
       const active = LOFI_PLAYLISTS.find((p) => p.id === id);
       if (active) {
+        try {
           playerRef.current.loadVideoById(active.videoId);
           playerRef.current.setVolume(Math.round(volume * 100));
-        playerRef.current.playVideo();
+        } catch {}
       }
     }
   };
 
   // Volume sync
   useEffect(() => {
-    if (playerRef.current && playerReady) {
+    try {
+      if (playerRef.current?.setVolume) {
         playerRef.current.setVolume(Math.round(volume * 100));
       }
-  }, [volume, playerReady]);
+    } catch {}
+  }, [volume]);
 
   return (
     <div className="p-4">
@@ -134,11 +138,8 @@ export default function MusicPlayer() {
         ))}
       </div>
 
-      {/* YouTube player: NOT display:none (API won't init). Offscreen instead. */}
-      <div
-        id="kira-youtube-player"
-        style={{ position: 'absolute', left: '-9999px', top: '-9999px', width: 1, height: 1 }}
-      />
+      {/* YouTube player: must have real dimensions for the API to work */}
+      <div id="kira-youtube-player" style={{ width: 1, height: 1, opacity: 0, position: 'absolute', pointerEvents: 'none' }} />
 
       <div className="relative rounded-xl overflow-hidden bg-white/30" style={{ height: 60 }}>
         {!started ? (
@@ -151,7 +152,7 @@ export default function MusicPlayer() {
           </button>
         ) : (
           <div className="w-full h-full flex items-center justify-center text-kira-plum/40 text-xs gap-2">
-            <span className="w-2 h-2 rounded-full bg-kira-mint animate-pulse inline-block" />
+            <span className={`w-2 h-2 rounded-full animate-pulse inline-block ${playing ? 'bg-kira-mint' : 'bg-kira-plum/30'}`} />
             <span>playing {LOFI_PLAYLISTS.find((p) => p.id === activeId)?.name}</span>
           </div>
         )}

frontend/src/components/WhiteNoise.tsx

@@ -1,201 +1,194 @@
-import { useState, useRef, useCallback, useEffect } from 'react';
+import { useState, useRef, useEffect, useCallback } from 'react';
+import { Howl } from 'howler';
 
-type NoiseType = 'white' | 'pink' | 'brown' | 'rain' | 'cafe';
+interface AmbientSound {
+  id: string;
+  label: string;
+  icon: string;
+  src: string;
+}
 
-const NOISE_PRESETS: { id: NoiseType; label: string; icon: string }[] = [
-  { id: 'white', label: 'White', icon: '⚪' },
-  { id: 'pink', label: 'Pink', icon: '🌸' },
-  { id: 'brown', label: 'Brown', icon: '🤎' },
-  { id: 'rain', label: 'Rain', icon: '🌧️' },
-  { id: 'cafe', label: 'Cafe', icon: '☕' },
+interface Category {
+  id: string;
+  label: string;
+  icon: string;
+  sounds: AmbientSound[];
+}
+
+const CATEGORIES: Category[] = [
+  {
+    id: 'noise', label: 'Noise', icon: '🔉',
+    sounds: [
+      { id: 'white-noise', label: 'White', icon: '⚪', src: '/sounds/noise/white-noise.wav' },
+      { id: 'pink-noise', label: 'Pink', icon: '🌸', src: '/sounds/noise/pink-noise.wav' },
+      { id: 'brown-noise', label: 'Brown', icon: '🤎', src: '/sounds/noise/brown-noise.wav' },
+    ],
+  },
+  {
+    id: 'rain', label: 'Rain', icon: '🌧️',
+    sounds: [
+      { id: 'light-rain', label: 'Light', icon: '🌦️', src: '/sounds/rain/light-rain.mp3' },
+      { id: 'heavy-rain', label: 'Heavy', icon: '⛈️', src: '/sounds/rain/heavy-rain.mp3' },
+      { id: 'rain-on-window', label: 'Window', icon: '🪟', src: '/sounds/rain/rain-on-window.mp3' },
+      { id: 'thunder', label: 'Thunder', icon: '⚡', src: '/sounds/rain/thunder.mp3' },
+      { id: 'rain-on-tent', label: 'Tent', icon: '⛺', src: '/sounds/rain/rain-on-tent.mp3' },
+    ],
+  },
+  {
+    id: 'nature', label: 'Nature', icon: '🌿',
+    sounds: [
+      { id: 'waves', label: 'Waves', icon: '🌊', src: '/sounds/nature/waves.mp3' },
+      { id: 'campfire', label: 'Campfire', icon: '🔥', src: '/sounds/nature/campfire.mp3' },
+      { id: 'river', label: 'River', icon: '🏞️', src: '/sounds/nature/river.mp3' },
+      { id: 'wind', label: 'Wind', icon: '💨', src: '/sounds/nature/wind.mp3' },
+      { id: 'jungle', label: 'Jungle', icon: '🌴', src: '/sounds/nature/jungle.mp3' },
+    ],
+  },
+  {
+    id: 'places', label: 'Places', icon: '☕',
+    sounds: [
+      { id: 'cafe', label: 'Cafe', icon: '☕', src: '/sounds/places/cafe.mp3' },
+      { id: 'library', label: 'Library', icon: '📚', src: '/sounds/places/library.mp3' },
+      { id: 'office', label: 'Office', icon: '🏢', src: '/sounds/places/office.mp3' },
+      { id: 'restaurant', label: 'Restaurant', icon: '🍽️', src: '/sounds/places/restaurant.mp3' },
+    ],
+  },
+  {
+    id: 'things', label: 'Things', icon: '🎵',
+    sounds: [
+      { id: 'keyboard', label: 'Keyboard', icon: '⌨️', src: '/sounds/things/keyboard.mp3' },
+      { id: 'clock', label: 'Clock', icon: '🕐', src: '/sounds/things/clock.mp3' },
+      { id: 'ceiling-fan', label: 'Fan', icon: '🌀', src: '/sounds/things/ceiling-fan.mp3' },
+      { id: 'vinyl-effect', label: 'Vinyl', icon: '💿', src: '/sounds/things/vinyl-effect.mp3' },
+      { id: 'wind-chimes', label: 'Chimes', icon: '🎐', src: '/sounds/things/wind-chimes.mp3' },
+    ],
+  },
+  {
+    id: 'animals', label: 'Animals', icon: '🐾',
+    sounds: [
+      { id: 'birds', label: 'Birds', icon: '🐦', src: '/sounds/animals/birds.mp3' },
+      { id: 'cat-purring', label: 'Cat', icon: '🐱', src: '/sounds/animals/cat-purring.mp3' },
+      { id: 'crickets', label: 'Crickets', icon: '🦗', src: '/sounds/animals/crickets.mp3' },
+      { id: 'owl', label: 'Owl', icon: '🦉', src: '/sounds/animals/owl.mp3' },
+      { id: 'whale', label: 'Whale', icon: '🐋', src: '/sounds/animals/whale.mp3' },
+    ],
+  },
 ];
 
 export default function WhiteNoise() {
-  const [active, setActive] = useState<NoiseType | null>(null);
-  const [volume, setVolume] = useState(0.25);
-  const ctxRef = useRef<AudioContext | null>(null);
-  const gainRef = useRef<GainNode | null>(null);
-  const sourceRef = useRef<AudioBufferSourceNode | null>(null);
-  // For rain/cafe: extra nodes to tear down
-  const extraNodesRef = useRef<AudioNode[]>([]);
+  const [activeTab, setActiveTab] = useState<string>('noise');
+  const [playing, setPlaying] = useState<Record<string, number>>({}); // id -> volume 0-1
+  const howlsRef = useRef<Map<string, Howl>>(new Map());
 
-  const stopNoise = useCallback(() => {
-    if (sourceRef.current) {
-      try { sourceRef.current.stop(); } catch {}
-      sourceRef.current.disconnect();
-      sourceRef.current = null;
+  const activeCategory = CATEGORIES.find((c) => c.id === activeTab) ?? CATEGORIES[0];
+
+  const toggle = useCallback((sound: AmbientSound) => {
+    const existing = howlsRef.current.get(sound.id);
+    if (existing && existing.playing()) {
+      existing.fade(existing.volume(), 0, 300);
+      setTimeout(() => {
+        existing.stop();
+        existing.unload();
+        howlsRef.current.delete(sound.id);
+      }, 300);
+      setPlaying((prev) => {
+        const next = { ...prev };
+        delete next[sound.id];
+        return next;
+      });
+    } else {
+      const howl = new Howl({
+        src: [sound.src],
+        loop: true,
+        volume: 0.5,
+        html5: true,
+      });
+      howl.fade(0, 0.5, 300);
+      howl.play();
+      howlsRef.current.set(sound.id, howl);
+      setPlaying((prev) => ({ ...prev, [sound.id]: 0.5 }));
     }
-    extraNodesRef.current.forEach((n) => { try { n.disconnect(); } catch {} });
-    extraNodesRef.current = [];
-    setActive(null);
   }, []);
 
-  const startNoise = useCallback((type: NoiseType) => {
-    stopNoise();
+  const setSoundVolume = useCallback((id: string, vol: number) => {
+    const howl = howlsRef.current.get(id);
+    if (howl) howl.volume(vol);
+    setPlaying((prev) => ({ ...prev, [id]: vol }));
+  }, []);
 
-    const ctx = ctxRef.current || new (window.AudioContext || (window as any).webkitAudioContext)();
-    ctxRef.current = ctx;
-    if (ctx.state === 'suspended') ctx.resume();
-
-    const sr = ctx.sampleRate;
-    // 10-second buffer — long enough to avoid obvious loops, short enough to generate fast
-    const len = 10 * sr;
-    const buf = ctx.createBuffer(2, len, sr); // stereo for spatial depth
-
-    for (let ch = 0; ch < 2; ch++) {
-      const d = buf.getChannelData(ch);
-      if (type === 'white') {
-        for (let i = 0; i < len; i++) d[i] = Math.random() * 2 - 1;
-      } else if (type === 'pink') {
-        // Paul Kellet's pink noise filter (industry standard)
-        let b0 = 0, b1 = 0, b2 = 0, b3 = 0, b4 = 0, b5 = 0, b6 = 0;
-        for (let i = 0; i < len; i++) {
-          const w = Math.random() * 2 - 1;
-          b0 = 0.99886 * b0 + w * 0.0555179;
-          b1 = 0.99332 * b1 + w * 0.0750759;
-          b2 = 0.96900 * b2 + w * 0.1538520;
-          b3 = 0.86650 * b3 + w * 0.3104856;
-          b4 = 0.55000 * b4 + w * 0.5329522;
-          b5 = -0.7616 * b5 - w * 0.0168980;
-          d[i] = (b0 + b1 + b2 + b3 + b4 + b5 + b6 + w * 0.5362) * 0.11;
-          b6 = w * 0.115926;
-        }
-      } else if (type === 'brown') {
-        // Brownian motion (integrated white noise)
-        let last = 0;
-        for (let i = 0; i < len; i++) {
-          last += (Math.random() * 2 - 1) * 0.02;
-          last = Math.max(-1, Math.min(1, last)); // clamp
-          d[i] = last;
-        }
-      } else if (type === 'rain') {
-        // Layered: low rumble (brown) + random droplet clicks
-        let last = 0;
-        for (let i = 0; i < len; i++) {
-          const w = Math.random() * 2 - 1;
-          // Brown base for rumble
-          last += w * 0.005;
-          last *= 0.998;
-          // Random droplet pings (sparse impulses filtered)
-          const drop = Math.random() < 0.0008 ? (Math.random() * 0.6 + 0.2) : 0;
-          d[i] = last * 0.6 + drop * Math.sin(i * 0.13 + ch) * 0.4;
-        }
-      } else if (type === 'cafe') {
-        // Low brown hum + scattered high transients (clatter)
-        let last = 0;
-        for (let i = 0; i < len; i++) {
-          const w = Math.random() * 2 - 1;
-          last += w * 0.003;
-          last *= 0.999;
-          // Occasional clatter
-          const clatter = Math.random() < 0.0005 ? (Math.random() * 0.4 + 0.1) * Math.sin(i * 0.47) : 0;
-          // Distant murmur (band-limited noise burst)
-          const murmur = Math.random() * 0.02;
-          d[i] = last * 0.5 + clatter + murmur;
-        }
-      }
-    }
-
-    // Crossfade start/end for seamless loop
-    const fade = Math.min(sr * 0.05, len / 4); // 50ms fade
-    for (let i = 0; i < fade; i++) {
-      const t = i / fade;
-      for (let ch = 0; ch < 2; ch++) {
-        const d = buf.getChannelData(ch);
-        d[i] *= t; // fade in
-        d[len - 1 - i] *= t; // fade out
-      }
-    }
-
-    const src = ctx.createBufferSource();
-    src.buffer = buf;
-    src.loop = true;
-
-    const gain = ctx.createGain();
-    gain.gain.value = volume;
-
-    let tail: AudioNode = src;
-
-    // For rain/cafe: add filtering for warmth
-    if (type === 'rain') {
-      const lp = ctx.createBiquadFilter();
-      lp.type = 'lowpass';
-      lp.frequency.value = 6000;
-      lp.Q.value = 0.5;
-      tail.connect(lp);
-      tail = lp;
-      extraNodesRef.current.push(lp);
-    } else if (type === 'cafe') {
-      const bp = ctx.createBiquadFilter();
-      bp.type = 'lowpass';
-      bp.frequency.value = 3000;
-      bp.Q.value = 0.8;
-      tail.connect(bp);
-      tail = bp;
-      extraNodesRef.current.push(bp);
-    }
-
-    tail.connect(gain);
-    gain.connect(ctx.destination);
-    src.start();
-
-    sourceRef.current = src;
-    gainRef.current = gain;
-    setActive(type);
-  }, [volume, stopNoise]);
-
-  const toggle = (type: NoiseType) => {
-    if (active === type) stopNoise();
-    else startNoise(type);
+  // Cleanup all on unmount
+  useEffect(() => {
+    return () => {
+      howlsRef.current.forEach((h) => { try { h.stop(); h.unload(); } catch {} });
+      howlsRef.current.clear();
     };
-
-  const changeVolume = (v: number) => {
-    setVolume(v);
-    if (gainRef.current) gainRef.current.gain.value = v;
-  };
-
-  // Cleanup on unmount
-  useEffect(() => () => {
-    stopNoise();
-    ctxRef.current?.close().catch(() => {});
-  }, [stopNoise]);
+  }, []);
 
   return (
     <div className="p-4">
       <h3 className="text-sm font-bold text-kira-plum mb-3 flex items-center gap-2">
-        <span>🌬️</span> White Noise
+        <span>🌬️</span> Ambient
       </h3>
-      <div className="flex flex-wrap gap-2 mb-3">
-        {NOISE_PRESETS.map((p) => (
+
+      {/* Category tabs */}
+      <div className="flex gap-1 mb-3 flex-wrap">
+        {CATEGORIES.map((cat) => (
           <button
-            key={p.id}
-            onClick={() => toggle(p.id)}
-            className={`text-xs px-3 py-1.5 rounded-full transition-all flex items-center gap-1 ${
-              active === p.id
-                ? 'bg-kira-pink text-white shadow'
-                : 'bg-white/50 text-kira-plum/70 hover:bg-kira-glow'
+            key={cat.id}
+            onClick={() => setActiveTab(cat.id)}
+            className={`text-[10px] px-2 py-1 rounded-lg transition-all flex items-center gap-1 ${
+              activeTab === cat.id
+                ? 'bg-kira-pink/20 text-kira-pink font-bold'
+                : 'text-kira-plum/40 hover:text-kira-plum/60'
             }`}
           >
-            <span>{p.icon}</span>
-            <span>{p.label}</span>
+            <span>{cat.icon}</span>
+            <span>{cat.label}</span>
           </button>
         ))}
       </div>
-      <div className="flex items-center gap-2 text-xs text-kira-plum/60">
-        <span>Vol</span>
+
+      {/* Sound grid */}
+      <div className="flex flex-col gap-2">
+        {activeCategory.sounds.map((sound) => {
+          const vol = playing[sound.id];
+          const isActive = vol !== undefined;
+          return (
+            <div key={sound.id} className="flex items-center gap-2">
+              <button
+                onClick={() => toggle(sound)}
+                className={`shrink-0 w-8 h-8 rounded-lg flex items-center justify-center text-sm transition-all ${
+                  isActive
+                    ? 'bg-kira-pink text-white shadow'
+                    : 'bg-white/40 text-kira-plum/50 hover:bg-white/60'
+                }`}
+              >
+                {sound.icon}
+              </button>
+              <span className={`text-[11px] w-14 shrink-0 ${isActive ? 'text-kira-plum font-medium' : 'text-kira-plum/40'}`}>
+                {sound.label}
+              </span>
+              {isActive && (
                 <input
                   type="range"
                   min={0}
-          max={0.6}
+                  max={1}
                   step={0.02}
-          value={volume}
-          onChange={(e) => changeVolume(parseFloat(e.target.value))}
+                  value={vol}
+                  onChange={(e) => setSoundVolume(sound.id, parseFloat(e.target.value))}
                   className="flex-1 accent-kira-pink"
                 />
-        <span className="tabular-nums w-8 text-right">{Math.round(volume * 100)}%</span>
+              )}
+            </div>
+          );
+        })}
+      </div>
+
+      {/* Active sounds count */}
+      {Object.keys(playing).length > 0 && (
+        <div className="mt-2 text-[10px] text-kira-mint/70">
+          {Object.keys(playing).length} sound{Object.keys(playing).length > 1 ? 's' : ''} mixing ✨
         </div>
-      {active && (
-        <div className="mt-2 text-[10px] text-kira-mint/70">Playing {active} noise — body double approved ✨</div>
       )}
     </div>
   );