body { font-family: sans-serif; margin: 0; }
header { background: #f8f9fa; padding: 20px; text-align: center; }
.product-card { border: 1px solid #ddd; padding: 20px; border-radius: 8px; text-align: center; width: 200px; }
button { padding: 10px; cursor: pointer; background: #007bff; color: white; border: none; border-radius: 4px; }
button:hover { background: #0056b3; }
@media(max-width:768px) { .product-card { width: 100%; } }