fix: collapsible bottom sheet + pinch-to-zoom on mobile

- Bottom sheet starts collapsed (handle bar only), swipe up to expand
- Tabs visible when collapsed in puzzle view, content hidden
- Swipe down or tap handle to collapse
- Add usePinchZoom hook: two-finger pinch gesture controls canvas zoom
- Pinch zoom wired into both Sandbox and Puzzle View canvases

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/App.jsx

@@ -11,6 +11,7 @@ import PresetModal from './components/PresetModal.jsx';
 import BottomSheet from './components/BottomSheet.jsx';
 import { CHIPTUNE_PRESET } from './presets/chiptune.js';
 import { useIsMobile } from './hooks/useIsMobile.js';
+import { usePinchZoom } from './hooks/usePinchZoom.js';
 import { getModulesByCategory } from './engine/moduleRegistry.js';
 
 export default function App({ onSwitchToGame }) {
@@ -24,6 +25,11 @@ export default function App({ onSwitchToGame }) {
   const isMobile = useIsMobile();
   const [menuOpen, setMenuOpen] = useState(false);
 
+  // Pinch-to-zoom on mobile
+  const getZoom = useCallback(() => state.zoom, []);
+  const setZoom = useCallback((z) => { state.zoom = z; emit(); }, []);
+  usePinchZoom(containerRef, getZoom, setZoom);
+
   // Subscribe to state changes
   useEffect(() => {
     const unsub = subscribe(() => forceUpdate(n => n + 1));

src/components/BottomSheet.jsx

@@ -3,7 +3,6 @@ import { useState, useRef, useCallback } from 'react';
 export default function BottomSheet({ tabs, activeTab, onTabChange, children, className = '' }) {
   const [expanded, setExpanded] = useState(false);
   const startY = useRef(0);
-  const sheetRef = useRef(null);
 
   const handleTouchStart = useCallback((e) => {
     startY.current = e.touches[0].clientY;
@@ -11,28 +10,30 @@ export default function BottomSheet({ tabs, activeTab, onTabChange, children, cl
 
   const handleTouchEnd = useCallback((e) => {
     const deltaY = e.changedTouches[0].clientY - startY.current;
-    if (deltaY < -40) setExpanded(true);
-    if (deltaY > 40) setExpanded(false);
+    if (deltaY < -30) setExpanded(true);
+    if (deltaY > 30) setExpanded(false);
   }, []);
 
   return (
     <div
-      ref={sheetRef}
-      className={`bottom-sheet ${expanded ? 'expanded' : ''} ${className}`}
+      className={`bottom-sheet ${expanded ? 'expanded' : 'collapsed'} ${className}`}
       onTouchStart={handleTouchStart}
       onTouchEnd={handleTouchEnd}
     >
-      <div className="bottom-sheet-handle" onClick={() => setExpanded(e => !e)}>
+      <div className="bottom-sheet-handle" onClick={() => setExpanded(v => !v)}>
         <div className="bottom-sheet-handle-bar" />
+        {!expanded && !tabs && (
+          <span className="bottom-sheet-peek-label">Modulos ▲</span>
+        )}
       </div>
 
       {tabs && tabs.length > 0 && (
-        <div className="bottom-sheet-tabs">
+        <div className="bottom-sheet-tabs" onClick={() => !expanded && setExpanded(true)}>
           {tabs.map(tab => (
             <button
               key={tab.id}
               className={`bottom-sheet-tab ${activeTab === tab.id ? 'active' : ''}`}
-              onClick={() => onTabChange?.(tab.id)}
+              onClick={() => { onTabChange?.(tab.id); setExpanded(true); }}
             >
               {tab.label}
               {activeTab === tab.id && <div className="bottom-sheet-tab-line" />}
@@ -41,9 +42,11 @@ export default function BottomSheet({ tabs, activeTab, onTabChange, children, cl
         </div>
       )}
 
+      {expanded && (
         <div className="bottom-sheet-content">
           {children}
         </div>
+      )}
     </div>
   );
 }

src/game/PuzzleView.jsx

@@ -6,6 +6,7 @@ import ModuleNode from '../components/ModuleNode.jsx';
 import WireLayer from '../components/WireLayer.jsx';
 import BottomSheet from '../components/BottomSheet.jsx';
 import { useIsMobile } from '../hooks/useIsMobile.js';
+import { usePinchZoom } from '../hooks/usePinchZoom.js';
 import { playTarget, stopTarget, isTargetPlaying } from './targetAudio.js';
 import LevelComplete from './LevelComplete.jsx';
 import { completeLevel, saveLevelPatch, getLevelPatch, clearLevelPatch, markHintUsed, wasHintUsed } from './gameState.js';
@@ -25,6 +26,11 @@ export default function PuzzleView({ level, levelIndex, worldLevels, onBack, onN
   const isMobile = useIsMobile();
   const [mobileTab, setMobileTab] = useState('mission');
 
+  // Pinch-to-zoom on mobile
+  const getZoom = useCallback(() => state.zoom, []);
+  const setZoom = useCallback((z) => { state.zoom = z; emit(); }, []);
+  usePinchZoom(containerRef, getZoom, setZoom);
+
   useEffect(() => {
     const unsub = subscribe(() => {
       forceUpdate(n => n + 1);

src/hooks/usePinchZoom.js

@@ -0,0 +1,48 @@
+import { useRef, useEffect } from 'react';
+
+export function usePinchZoom(containerRef, getZoom, setZoom) {
+  const pinchRef = useRef({ active: false, startDist: 0, startZoom: 1 });
+
+  useEffect(() => {
+    const el = containerRef.current;
+    if (!el) return;
+
+    const getDistance = (t1, t2) =>
+      Math.sqrt((t1.clientX - t2.clientX) ** 2 + (t1.clientY - t2.clientY) ** 2);
+
+    const onTouchStart = (e) => {
+      if (e.touches.length === 2) {
+        e.preventDefault();
+        pinchRef.current = {
+          active: true,
+          startDist: getDistance(e.touches[0], e.touches[1]),
+          startZoom: getZoom(),
+        };
+      }
+    };
+
+    const onTouchMove = (e) => {
+      if (pinchRef.current.active && e.touches.length === 2) {
+        e.preventDefault();
+        const dist = getDistance(e.touches[0], e.touches[1]);
+        const scale = dist / pinchRef.current.startDist;
+        const newZoom = Math.max(0.3, Math.min(3, pinchRef.current.startZoom * scale));
+        setZoom(newZoom);
+      }
+    };
+
+    const onTouchEnd = () => {
+      pinchRef.current.active = false;
+    };
+
+    el.addEventListener('touchstart', onTouchStart, { passive: false });
+    el.addEventListener('touchmove', onTouchMove, { passive: false });
+    el.addEventListener('touchend', onTouchEnd);
+
+    return () => {
+      el.removeEventListener('touchstart', onTouchStart);
+      el.removeEventListener('touchmove', onTouchMove);
+      el.removeEventListener('touchend', onTouchEnd);
+    };
+  }, [containerRef, getZoom, setZoom]);
+}

src/index.css

@@ -873,19 +873,26 @@ html, body, #root {
     display: flex; flex-direction: column;
     background: var(--panel); border-top: 1px solid var(--border);
     border-radius: 16px 16px 0 0; flex-shrink: 0;
-    max-height: 40vh; transition: max-height 0.3s ease;
+    transition: max-height 0.3s ease;
     overflow: hidden;
   }
-  .bottom-sheet.expanded { max-height: 60vh; }
+  .bottom-sheet.collapsed { max-height: 42px; }
+  .bottom-sheet.collapsed:has(.bottom-sheet-tabs) { max-height: 76px; }
+  .bottom-sheet.expanded { max-height: 55vh; }
 
   .bottom-sheet-handle {
-    display: flex; justify-content: center; padding: 10px 0 6px;
-    cursor: grab;
+    display: flex; align-items: center; justify-content: center;
+    gap: 8px; padding: 10px 0 6px; cursor: pointer; min-height: 34px;
   }
   .bottom-sheet-handle-bar {
     width: 40px; height: 4px; background: var(--border);
     border-radius: 2px;
   }
+  .bottom-sheet-peek-label {
+    font-size: 10px; font-weight: 600; color: var(--text2);
+    font-family: 'JetBrains Mono', monospace; letter-spacing: 1px;
+    text-transform: uppercase;
+  }
 
   .bottom-sheet-tabs {
     display: flex; padding: 0 16px; gap: 0;