:root{font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,sans-serif;color:#f4f4f6;background:#13141a}*{box-sizing:border-box}body{margin:0;background:#13141a}.app{max-width:520px;margin:0 auto;padding:16px}.card{background:#20222d;border:1px solid #2f3242;border-radius:12px;padding:14px;margin-top:12px}.muted{color:#a9aec5}.error{color:#ff8a8a}label{display:flex;flex-direction:column;gap:6px;margin-bottom:10px}input,button{border-radius:8px;border:1px solid #3b4052;padding:10px;font-size:16px}button{background:#4d7cff;color:#fff;border:none;margin-top:6px}button:disabled{opacity:.6}.row{display:flex;gap:8px;margin:12px 0}.row input{flex:1}.board-grid{display:grid;gap:8px;margin-top:12px}.board-cell{min-height:56px;border-radius:10px;background:#2b3040;border:1px solid #3d4358;display:grid;place-content:center;font-size:22px;font-weight:700}.confetti{font-size:20px}@media (max-width: 480px){.app{padding:10px}.board-cell{min-height:50px}}