body { background: #000; color: white; font-family: sans-serif; text-align: center; }
.grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 10px; max-width: 600px; margin: 20px auto; padding: 10px; }
.card { background: #00ffff; color: #000; aspect-ratio: 1; display: flex; align-items: center; justify-content: center; font-size: 0.8rem; padding: 5px; cursor: pointer; border-radius: 4px; transition: 0.3s; }
.card.selected { background: #2ecc71; font-weight: bold; }