/* Reset và biến cơ bản */
:root {
    --primary-color: #c92424;
    --secondary-color: #28a745;
    --bg-color: #f4f4f4;
    --text-color: #333;
    --accent-color: #007bff;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
}

/* Header */
header {
    background-color: var(--primary-color);
    color: #fff;
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 5px rgba(49, 35, 143, 0.1);
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

nav ul {
    list-style: none;
    display: flex;
}

nav ul li {
    margin: 0 1rem;
}

nav ul li a {
    color: #fff;
    text-decoration: none;
    transition: color 0.3s, transform 0.3s;
}

nav ul li a:hover {
    color: var(--secondary-color);
    transform: scale(1.1);
}

/* Main */
main .container {
    display: flex;
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 1rem;
}

.sidebar {
    flex: 1;
    padding: 1rem;
    background-color: #fff;
    border-radius: 8px;
    margin-right: 2rem;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.products {
    flex: 3;
}

.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.product {
    background-color: #fff;
    border: 1px solid #ddd;
    border-radius: 8px;
    padding: 1rem;
    text-align: center;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s, box-shadow 0.3s;
    animation: fadeIn 0.5s ease-in forwards;
    opacity: 0;
    transform: translateY(20px);
}

.product:nth-child(1) { animation-delay: 0.1s; }
.product:nth-child(2) { animation-delay: 0.2s; }
.product:nth-child(3) { animation-delay: 0.3s; }
.product:nth-child(4) { animation-delay: 0.4s; }
.product:nth-child(5) { animation-delay: 0.5s; }
.product:nth-child(6) { animation-delay: 0.6s; }

.product:hover {
    transform: translateY(-5px) scale(1.02);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.product img {
    width: 184px;
    height: 184px;
    object-fit: cover;
    border-radius: 8px;
    transition: transform 0.3s;
    display: block;
    margin: 0.6rem auto;
}

.product img:hover {
    transform: scale(1.1);
}

.product h3 {
    margin: 1rem 0;
    transition: color 0.3s;
}

.product h3:hover {
    color: var(--accent-color);
}

.product p {
    margin-bottom: 0.5rem;
    color: #666;
}
.btn {
    background-color: var(--secondary-color);
    color: #fff;
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 4px;
    text-decoration: none;
    display: inline-block;
    margin: 0.5rem;
    transition: background-color 0.3s, transform 0.3s;
}

.btn:hover {
    background-color: #218838;
    transform: translateY(-2px);
}

/* Nút mua*/
.btn-buy {
    --bg-start: var(--secondary-color);
    --bg-end: #1fa35a;
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.6rem 1rem;
    background: linear-gradient(90deg, var(--bg-start), var(--bg-end));
    color: #fff;
    border: 0;
    border-radius: 999px;
    box-shadow: 0 8px 20px rgba(31,163,90,0.18), inset 0 -2px 0 rgba(0,0,0,0.06);
    font-weight: 700;
    cursor: pointer;
    text-decoration: none;
    transition: transform 0.14s ease, box-shadow 0.14s ease, opacity 0.14s ease;
}
.btn-buy svg { width: 18px; height: 18px; display: block; }
.btn-buy:focus {
    outline: 3px solid rgba(40,167,69,0.18);
    outline-offset: 3px;
}
.btn-buy:hover { transform: translateY(-2px) scale(1.01); box-shadow: 0 12px 28px rgba(31,163,90,0.22); }
.btn-buy:active { transform: translateY(0) scale(0.995); }

/* Optional price badge inside button */
.btn-buy .price {
    background: rgba(255,255,255,0.12);
    padding: 0.18rem 0.5rem;
    border-radius: 999px;
    font-weight: 700;
    font-size: 0.95rem;
}

/* Mobile: slightly smaller */
@media (max-width: 480px) {
    .btn-buy { padding: 0.5rem 0.8rem; gap: 0.45rem; }
    .btn-buy .price { font-size: 0.88rem; }
}
/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.product-detail .product-image img,
.product-hero img,
.product-detail img {
    width: 184px;
    height: 184px;
    object-fit: cover;
    border-radius: 8px;
    display: block;
    margin: 0 auto;
}

@media (max-width: 768px) {
    .product img,
    .product-detail .product-image img,
    .product-hero img,
    .product-detail img {
        width: 160px;
        height: 160px;
    }
}

.filter-group { margin-bottom: 1rem; }
.filter-title { font-weight: 600; margin-bottom: 0.5rem; }
.filter-list { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.filter-label {
    display: inline-block;
    padding: 0.35rem 0.6rem;
    background: #f0f0f0;
    border: 1px solid #e0e0e0;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.95rem;
    transition: background-color 0.18s, color 0.18s, border-color 0.18s;
}
.filter-label:hover { background: #e9f7ef; }
.products .product { display: none; }
#brand-any:checked ~ #price-any:checked ~ .products .product { display: block; }
#brand-any:checked ~ #price-10-15:checked ~ .products .product[data-price="10-15"] { display: block; }
#brand-any:checked ~ #price-15-20:checked ~ .products .product[data-price="15-20"] { display: block; }
#brand-any:checked ~ #price-20-30:checked ~ .products .product[data-price="20-30"] { display: block; }

#brand-Apple:checked ~ #price-any:checked ~ .products .product[data-brand="Apple"] { display: block; }
#brand-Samsung:checked ~ #price-any:checked ~ .products .product[data-brand="Samsung"] { display: block; }
#brand-Xiaomi:checked ~ #price-any:checked ~ .products .product[data-brand="Xiaomi"] { display: block; }
#brand-Oppo:checked ~ #price-any:checked ~ .products .product[data-brand="Oppo"] { display: block; }
#brand-Google:checked ~ #price-any:checked ~ .products .product[data-brand="Google"] { display: block; }
#brand-OnePlus:checked ~ #price-any:checked ~ .products .product[data-brand="OnePlus"] { display: block; }

#brand-Apple:checked ~ #price-20-30:checked ~ .products .product[data-brand="Apple"][data-price="20-30"] { display: block; }
#brand-Samsung:checked ~ #price-20-30:checked ~ .products .product[data-brand="Samsung"][data-price="20-30"] { display: block; }
#brand-Xiaomi:checked ~ #price-10-15:checked ~ .products .product[data-brand="Xiaomi"][data-price="10-15"] { display: block; }
#brand-Oppo:checked ~ #price-15-20:checked ~ .products .product[data-brand="Oppo"][data-price="15-20"] { display: block; }
#brand-Google:checked ~ #price-20-30:checked ~ .products .product[data-brand="Google"][data-price="20-30"] { display: block; }
#brand-OnePlus:checked ~ #price-15-20:checked ~ .products .product[data-brand="OnePlus"][data-price="15-20"] { display: block; }

#brand-any:checked ~ aside .filter-label[for="brand-any"],
#brand-Apple:checked ~ aside .filter-label[for="brand-Apple"],
#brand-Samsung:checked ~ aside .filter-label[for="brand-Samsung"],
#brand-Xiaomi:checked ~ aside .filter-label[for="brand-Xiaomi"],
#brand-Oppo:checked ~ aside .filter-label[for="brand-Oppo"],
#brand-Google:checked ~ aside .filter-label[for="brand-Google"],
#brand-OnePlus:checked ~ aside .filter-label[for="brand-OnePlus"] {
    background: var(--secondary-color);
    color: #fff;
    border-color: var(--secondary-color);
}

#price-any:checked ~ aside .filter-label[for="price-any"],
#price-10-15:checked ~ aside .filter-label[for="price-10-15"],
#price-15-20:checked ~ aside .filter-label[for="price-15-20"],
#price-20-30:checked ~ aside .filter-label[for="price-20-30"] {
    background: var(--secondary-color);
    color: #fff;
    border-color: var(--secondary-color);
}

/* Responsive */
@media (max-width: 768px) {
    main .container {
        flex-direction: column;
    }
    .sidebar {
        margin-right: 0;
        margin-bottom: 2rem;
    }
    nav ul {
        flex-direction: column;
    }
    nav ul li {
        margin: 0.5rem 0;
    }
    .product-grid {
        grid-template-columns: 1fr;
    }
}
/* Footer */
footer {
    background-color: var(--primary-color);
    color: #fff;
    text-align: center;
    padding: 1rem 0;
    margin-top: 2rem;
    box-shadow: 0 -2px 5px rgba(0, 0, 0, 0.1);
}