:root{--text:#6b6375;--text-h:#08060d;--bg:#faf8ef;--border:#e5e4e7;--shadow:#0000001a 0 10px 15px -3px, #0000000d 0 4px 6px -2px;--board-bg:#bbada0;--cell-bg:#cdc1b4;--tile-text:#776e65;--tile-text-light:#f9f6f2;--btn-bg:#8f7a66;--btn-bg-hover:#9f8b77;--btn-text:#f9f6f2;--score-label:#eee4da;--t2:#eee4da;--t4:#ede0c8;--t8:#f2b179;--t16:#f59563;--t32:#f67c5f;--t64:#f65e3b;--t128:#edcf72;--t256:#edcc61;--t512:#edc850;--t1024:#edc53f;--t2048:#edc22e;--tbig:#3c3a32;--overlay:#eee4daba;--overlay-win:#edc22e80;--sans:system-ui, "Segoe UI", Roboto, sans-serif;--mono:ui-monospace, Consolas, monospace;font:18px/145% var(--sans);letter-spacing:.18px;color:var(--text);background:var(--bg);font-synthesis:none;text-rendering:optimizelegibility;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}@media (prefers-color-scheme:dark){:root{--bg:#16171d;--board-bg:#2e2b28;--cell-bg:#3a3633;--tile-text:#e8e2d6;--tile-text-light:#1a1714;--btn-bg:#6f6256;--btn-bg-hover:#7d6e61;--btn-text:#f3ede4;--score-label:#d9cfc2;--t2:#4a4640;--t4:#534e46;--t8:#8a5a3c;--t16:#97543a;--t32:#a8463a;--t64:#b23d2f;--t128:#9c7b2e;--t256:#a07d2c;--t512:#a37f2a;--t1024:#a47e28;--t2048:#a87d22;--tbig:#c9a24a;--overlay:#141318c7;--overlay-win:#a87d2273;--shadow:#0006 0 10px 15px -3px, #00000040 0 4px 6px -2px}}body{margin:0}main{box-sizing:border-box;max-width:500px;margin:0 auto;padding:24px 16px 48px}header{justify-content:space-between;align-items:center;gap:16px;display:flex}h1{font-family:var(--sans);color:var(--tile-text);letter-spacing:-2px;margin:0;font-size:56px;font-weight:800}.intro{color:var(--tile-text);margin:16px 0}.intro strong{color:var(--tile-text)}.controls{flex-wrap:wrap;justify-content:flex-end;align-items:center;gap:10px;margin-bottom:12px;display:flex}.controls button,.overlay-actions button{background:var(--btn-bg);color:var(--btn-text);cursor:pointer;border:none;border-radius:6px;padding:10px 18px;font-size:15px;font-weight:700;transition:background .2s}:is(.controls button,.overlay-actions button):hover{background:var(--btn-bg-hover)}.controls .ai-toggle.running{background:#c0392b}.controls .ai-toggle.running:hover{background:#a93226}