:root{--bg: #1a1a2e;--surface: #16213e;--cell: #0f3460;--text: #eee;--text-dim: #888;--accent: #e94560;--cat: #FFD93D;--x-mark: rgba(255,255,255,.25);--region-a: rgba(233, 69, 96, .12);--region-b: rgba(83, 144, 217, .12);--region-c: rgba(78, 205, 196, .12);--region-d: rgba(255, 217, 61, .12);--region-e: rgba(168, 230, 207, .12);--region-f: rgba(200, 150, 255, .12);--highlight: rgba(255,255,255,.08);--error: #ff4757}[data-theme=light]{--bg: #FFF8E7;--surface: #f0e6d3;--cell: #ffffff;--text: #2d2d2d;--text-dim: #999;--cat: #FF6B6B;--x-mark: rgba(0,0,0,.15);--highlight: rgba(0,0,0,.04)}*{margin:0;padding:0;box-sizing:border-box}body{background:var(--bg);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;display:flex;justify-content:center;align-items:center;min-height:100dvh;user-select:none;-webkit-user-select:none;touch-action:manipulation}#app{display:flex;flex-direction:column;align-items:center;gap:16px;padding:16px;max-width:600px;width:100%}#header{display:flex;justify-content:space-between;align-items:center;width:100%;padding:0 4px}#level-info{font-size:14px;color:var(--text-dim)}#timer{font-family:monospace;font-size:14px;color:var(--text-dim)}#theme-toggle{background:none;border:none;font-size:18px;cursor:pointer;padding:4px 8px}#game-area{display:flex;justify-content:center;align-items:center}#grid-canvas{border-radius:8px;box-shadow:0 4px 24px #0000004d}#toolbar{display:flex;gap:12px}#toolbar button{width:52px;height:52px;border-radius:50%;border:1px solid var(--text-dim);background:var(--surface);color:var(--text);font-size:20px;cursor:pointer;display:flex;align-items:center;justify-content:center;transition:background .15s,transform .1s}#toolbar button:hover{background:var(--highlight)}#toolbar button:active{transform:scale(.92)}#overlay{position:fixed;inset:0;background:#0009;display:flex;align-items:center;justify-content:center;z-index:10}#overlay.hidden{display:none}#overlay-content{background:var(--surface);padding:32px;border-radius:16px;text-align:center;max-width:360px}#overlay-content h2{font-size:24px;margin-bottom:8px}#overlay-content p{color:var(--text-dim);margin-bottom:20px}#overlay-content button{padding:10px 32px;border-radius:8px;border:none;background:var(--accent);color:#fff;font-size:16px;cursor:pointer}.hint-text{color:var(--accent);font-weight:700;margin:8px 0}