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

/* Body & layout chính */
body {
    font-family: "Segoe UI", Arial, sans-serif;
    background: linear-gradient(135deg, #f2f2f2, #e8eef3);
    display: grid;
    grid-template-columns: 70% 30%;
    max-width: 1200px;
    margin: 0 auto;
}

/* Header */
header {
    background: linear-gradient(135deg, #c7cc19, #9fae00);
    color: #fff;
    padding: 25px;
    text-align: center;
    grid-column: 1 / span 2;
    font-size: 26px;
    font-weight: bold;
    letter-spacing: 1px;
}

/* Menu */
nav {
    background: #ffa486;
    text-align: center;
    padding: 12px 0;
    grid-column: 1 / span 2;
}

nav ul {
    list-style: none;
}

nav ul li {
    display: inline-block;
    margin: 0 15px;
}

nav ul li a {
    color: #fff;
    text-decoration: none;
    font-weight: 600;
    padding: 8px 12px;
    border-radius: 20px;
    transition: 0.3s;
}

nav ul li a:hover {
    background-color: rgba(255,255,255,0.3);
}

/* Danh sách sản phẩm */
.product-list {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
    padding: 25px;
}

/* Thẻ sản phẩm */
.product-card {
    background: #fff;
    border-radius: 12px;
    padding: 15px;
    text-align: center;
    box-shadow: 0 6px 15px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
}

.product-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.2);
}

.product-card img {
    max-width: 100%;
    height: auto;
    border-radius: 10px;
    margin-bottom: 10px;
}

/* Sidebar */
.sidebar {
    background: linear-gradient(135deg, #199cff, #0066cc);
    color: #fff;
    padding: 20px;
    border-radius: 10px;
    margin: 25px 15px 25px 0;
}

/* Social icons */
.social-icons {
    margin-top: 20px;
}

.social-icons a {
    color: #fff;
    text-decoration: none;
    display: block;
    padding: 8px;
    border-radius: 6px;
    transition: 0.3s;
}

.social-icons a:hover {
    background-color: rgba(255,255,255,0.2);
}

/* Button */
.button {
    background: linear-gradient(135deg, #04AA6D, #038f5b);
    border: none;
    color: white;
    padding: 12px 18px;
    text-align: center;
    text-decoration: none;
    font-size: 15px;
    margin: 6px 2px;
    cursor: pointer;
    transition: 0.3s;
}

.button:hover {
    opacity: 0.9;
    transform: scale(1.05);
}

.button1 { border-radius: 4px; }
.button3 { border-radius: 8px; }
.button4 { border-radius: 12px; }
.button5 { border-radius: 50%; }

/* Footer */
.footer {
    background: #333;
    color: #fff;
    text-align: center;
    padding: 25px;
    grid-column: 1 / span 2;
    display: grid;
}

.footer-item {
    padding: 10px;
}

/* Responsive */
@media (max-width: 768px) {
    body {
        grid-template-columns: 1fr;
    }

    .product-list {
        grid-template-columns: 1fr;
    }

    .sidebar {
        margin: 0 20px 20px;
    }

    .footer {
        grid-template-columns: 1fr;
    }
}
/* RESET */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* BODY */
body {
    font-family: "Poppins", "Segoe UI", Arial, sans-serif;
    background: linear-gradient(135deg, #eef2f7, #dce3ed);
    color: #333;
}

/* CONTAINER */
.container {
    max-width: 1200px;
    margin: 0 auto;
}

/* HEADER */
.header {
    background: linear-gradient(135deg, #0f2027, #203a43, #2c5364);
    color: #fff;
    padding: 35px 20px;
    text-align: center;
    border-radius: 0 0 25px 25px;
}

.header h1 {
    font-size: 32px;
    letter-spacing: 2px;
}

/* MAIN */
main {
    padding: 40px 20px;
}

/* PRODUCT DETAIL */
.product-detail {
    background: #fff;
    border-radius: 25px;
    padding: 30px;
    display: grid;
    grid-template-columns: 45% 55%;
    gap: 40px;
    box-shadow: 0 20px 50px rgba(0,0,0,0.15);
}

/* IMAGE */
.product-detail img {
    width: 100%;
    border-radius: 20px;
    transition: 0.4s ease;
}

.product-detail img:hover {
    transform: scale(1.05);
}

/* INFO */
.product-info h2 {
    font-size: 30px;
    color: #0f2027;
    margin-bottom: 10px;
}

.price {
    font-size: 26px;
    font-weight: bold;
    color: #e63946;
    margin-bottom: 20px;
}

/* DESCRIPTION */
.description {
    font-size: 16px;
    line-height: 1.8;
    background: #f7f9fc;
    padding: 20px;
    border-radius: 15px;
    margin-bottom: 25px;
}

.description strong {
    color: #0f2027;
}

/* BUTTONS */
.buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
}

.btn {
    text-decoration: none;
    padding: 14px 24px;
    border-radius: 30px;
    font-weight: 600;
    transition: 0.3s ease;
    text-align: center;
}

/* BUTTON STYLES */
.btn.primary {
    background: linear-gradient(135deg, #e63946, #ff6b6b);
    color: #fff;
}

.btn.primary:hover {
    transform: scale(1.1);
    box-shadow: 0 10px 25px rgba(230,57,70,0.5);
}

.btn.secondary {
    background: #0f2027;
    color: #fff;
}

.btn.secondary:hover {
    background: #2c5364;
}

.btn.back {
    background: #e5e7eb;
    color: #333;
}

.btn.back:hover {
    background: #d1d5db;
}

/* FOOTER */
.footer {
    margin-top: 50px;
    background: #0f2027;
    color: #fff;
    padding: 40px 20px;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    text-align: center;
    border-radius: 25px 25px 0 0;
}

.footer .col strong {
    font-size: 18px;
}

.footer .col p {
    margin-top: 8px;
    font-size: 14px;
    color: #cbd5e1;
}

/* RESPONSIVE */
@media (max-width: 768px) {
    .product-detail {
        grid-template-columns: 1fr;
    }

    .header h1 {
        font-size: 24px;
    }

    .product-info h2 {
        font-size: 24px;
    }

    .price {
        font-size: 22px;
    }

    .footer {
        grid-template-columns: 1fr;
        gap: 20px;
    }
}