.board{display:grid;grid-template-columns:repeat(auto-fit,minmax(70px,1fr));gap:12px;margin-top:1rem;max-width:360px;margin-inline:auto}.card{width:100%;aspect-ratio:1 / 1;background:#1e293b;border-radius:8px;display:flex;justify-content:center;align-items:center;font-size:2rem;cursor:pointer;-webkit-user-select:none;user-select:none;transition:transform .2s ease,background .2s ease}.card:hover{transform:scale(1.05)}.card.flipped{background:#7072cc}@media(max-width:480px){.card{font-size:1.5rem}}:root{font-family:system-ui,Avenir,Helvetica,Arial,sans-serif;line-height:1.5;font-weight:400;color-scheme:light dark;color:#ffffffde;background-color:#242424}body{margin:0;min-width:320px;min-height:100vh;display:flex;justify-content:center;align-items:center}h1{font-size:3em;text-align:center}button{margin-top:15px;border-radius:8px;border:1px solid transparent;padding:.6em 1.2em;font-size:1em;font-weight:500;background-color:#1a1a1a;color:#fff;cursor:pointer;transition:border-color .25s}button:hover{border-color:#646cff}