*{box-sizing:border-box}body{margin:0;min-width:320px;min-height:100vh;color:#1f2933;background:#f5f7fa;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif}button{border:1px solid #9aa6b2;border-radius:6px;background:#fff;color:#1f2933;font:inherit;cursor:pointer}button:focus-visible{outline:3px solid #74a9ff;outline-offset:2px}.app-shell{display:grid;min-height:100vh;place-items:center;padding:24px}.game-panel{width:min(100%,560px)}.game-header{display:flex;align-items:end;justify-content:space-between;gap:16px;margin-bottom:16px}.game-header h1{margin:0;font-size:clamp(1.75rem,6vw,2.5rem);line-height:1}.game-header p{margin:8px 0 0;color:#52616f}.score{min-width:96px;padding:8px 10px;border:1px solid #cbd2d9;border-radius:6px;background:#fff;text-align:center;font-weight:700}.board{display:grid;grid-template-columns:repeat(20,1fr);width:min(100%,560px);aspect-ratio:1;border:2px solid #323f4b;background:#e4e7eb}.cell{aspect-ratio:1;border:1px solid rgba(50,63,75,.12)}.snake{background:#2f855a}.head{background:#22543d}.food{background:#d64545;border-radius:50%}.actions{display:flex;gap:10px;margin-top:16px}.actions button{min-height:42px;padding:0 18px}.controls{display:grid;grid-template-columns:repeat(3,54px);grid-template-areas:". up ." "left down right";gap:8px;justify-content:center;margin-top:18px}.controls button{width:54px;height:48px;font-size:1.25rem;font-weight:700}.controls button:nth-child(1){grid-area:up}.controls button:nth-child(2){grid-area:left}.controls button:nth-child(3){grid-area:down}.controls button:nth-child(4){grid-area:right}@media(max-width:520px){.app-shell{padding:16px}.game-header{align-items:stretch;flex-direction:column}.score{width:100%}}