/* ==========================================================
   THEME: DREAMY BLUE LIGHT / BLUE MỘNG MƠ SÁNG & TRONG TRẺO
   Responsive Grid: 2 Cột trên Mobile | 4-6 Cột trên PC
   ========================================================== */
@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@400;500;600;700;800&display=swap');

:root {
    --bg-dark: #f0f4fc;             /* Nền mây xanh nhạt nhẹ nhàng */
    --bg-card: #ffffff;             /* Thẻ trắng tinh khôi */
    --bg-header: rgba(255, 255, 255, 0.85); /* Header mờ sương trong suốt */
    --accent-lapis: #8da9c4;         /* Xanh khói dịu mắt */
    --accent-blue: #4361ee;          /* Xanh lam mơ mộng làm nhấn */
    --accent-light-blue: #4895ef;    /* Xanh mây bồng bềnh */
    --accent-cyan: #2b2d42;          /* Tiêu đề xanh đậm sương đêm */
    --text-primary: #1e293b;        /* Chữ chính màu xanh xám đậm dễ đọc */
    --text-secondary: #64748b;      /* Chữ phụ màu xám xanh dịu */
    --price-gold: #e76f51;          /* Màu giá cam san hô nhẹ nhắn */
    --stock-green: #2a9d8f;         /* Green mint mát mắt */
    --out-red: #e63946;              /* Hồng đỏ pastel */
    --border-color: #e2e8f0;        /* Viền sáng mỏng mịn */
    --shadow-blue: rgba(67, 97, 238, 0.12); /* Đổ bóng phát sáng mộng mơ */
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

body {
    background-color: var(--bg-dark);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

a {
    color: var(--accent-light-blue);
    text-decoration: none;
    transition: all 0.3s ease;
}

a:hover {
    color: var(--accent-blue);
}

/* Header & Nav Bar */
header {
    background: var(--bg-header);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 12px 5%;
    box-shadow: 0 4px 20px rgba(67, 97, 238, 0.05);
}

.header-inner {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo a {
    font-size: 1.35rem;
    font-weight: 800;
    color: var(--accent-blue);
    display: flex;
    align-items: center;
    gap: 10px;
    letter-spacing: -0.5px;
    white-space: nowrap;
}

.logo i {
    color: var(--accent-light-blue);
    font-size: 1.5rem;
    filter: drop-shadow(0 0 8px var(--shadow-blue));
}

nav {
    display: flex;
    gap: 12px;
}

nav a {
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    border-radius: 8px;
    white-space: nowrap;
}

nav a:hover, nav a.active {
    color: var(--accent-blue);
    background-color: rgba(67, 97, 238, 0.08);
}

/* TỐI ƯU HEADER RIÊNG CHO MOBILE */
@media (max-width: 768px) {
    header {
        padding: 10px 15px;
    }

    .header-inner {
        flex-direction: column;
        gap: 10px;
        align-items: center;
    }

    .logo a {
        font-size: 1.15rem;
    }

    .logo i {
        font-size: 1.3rem;
    }

    nav {
        width: 100%;
        justify-content: center;
        gap: 6px;
        overflow-x: auto;
        padding-bottom: 2px;
    }

    nav a {
        font-size: 0.82rem;
        padding: 6px 12px;
        background: #ffffff;
        border-radius: 20px;
        border: 1px solid var(--border-color);
    }
}

/* Container */
.container {
    width: 92%;
    max-width: 1400px;
    margin: 20px auto;
    flex: 1;
}

/* Search Section */
.search-box {
    margin-bottom: 25px;
    display: flex;
    justify-content: center;
}

.search-box form {
    display: flex;
    width: 100%;
    max-width: 650px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 50px;
    padding: 6px 8px 6px 20px;
    box-shadow: 0 10px 25px rgba(67, 97, 238, 0.08);
    transition: all 0.3s ease;
}

.search-box form:focus-within {
    border-color: var(--accent-light-blue);
    box-shadow: 0 0 20px var(--shadow-blue);
}

.search-box input {
    width: 100%;
    background: transparent;
    border: none;
    outline: none;
    color: var(--text-primary);
    font-size: 0.95rem;
}

.search-box button {
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-light-blue));
    border: none;
    color: #fff;
    padding: 10px 20px;
    border-radius: 40px;
    font-weight: 700;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    box-shadow: 0 4px 12px rgba(67, 97, 238, 0.25);
}

.search-box button:hover {
    transform: scale(1.02);
    box-shadow: 0 6px 16px rgba(67, 97, 238, 0.35);
}

/* Product Grid: Mobile (2 Cột) | PC (4 - 6 Cột) */
.product-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
}

@media (min-width: 640px) {
    .product-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 20px;
    }
}

@media (min-width: 1024px) {
    .product-grid {
        grid-template-columns: repeat(4, 1fr);
        gap: 22px;
    }
}

@media (min-width: 1400px) {
    .product-grid {
        grid-template-columns: repeat(6, 1fr);
        gap: 20px;
    }
}

/* Product Card Styling */
.product-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 12px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.03);
}

.product-card:hover {
    transform: translateY(-6px);
    border-color: var(--accent-light-blue);
    box-shadow: 0 12px 30px rgba(67, 97, 238, 0.15);
}

.img-wrap {
    width: 100%;
    aspect-ratio: 1 / 1;
    background-color: #f8fafc;
    border-radius: 12px;
    overflow: hidden;
    position: relative;
    margin-bottom: 10px;
}

.img-wrap img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.product-card:hover .img-wrap img {
    transform: scale(1.08);
}

.badge {
    position: absolute;
    top: 8px;
    right: 8px;
    padding: 3px 8px;
    font-size: 0.7rem;
    font-weight: 700;
    border-radius: 6px;
    display: flex;
    align-items: center;
    gap: 4px;
    backdrop-filter: blur(4px);
}

.badge.stock-in {
    background-color: rgba(42, 157, 143, 0.12);
    color: var(--stock-green);
    border: 1px solid rgba(42, 157, 143, 0.25);
}

.badge.stock-out {
    background-color: rgba(230, 57, 70, 0.12);
    color: var(--out-red);
    border: 1px solid rgba(230, 57, 70, 0.25);
}

.product-info {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.product-card h3 {
    font-size: 0.92rem;
    font-weight: 600;
    color: var(--text-primary);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    height: 2.6em;
    line-height: 1.3;
}

.price {
    font-size: 1.1rem;
    font-weight: 800;
    color: var(--price-gold);
    display: flex;
    align-items: center;
    gap: 4px;
}

.time {
    font-size: 0.75rem;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 5px;
}

/* NÚT MŨI TÊN LÊN ĐẦU TRANG (BACK TO TOP) */
.back-to-top {
    position: fixed;
    bottom: 25px;
    right: 20px;
    width: 44px;
    height: 44px;
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-light-blue));
    color: #ffffff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    box-shadow: 0 6px 20px rgba(67, 97, 238, 0.3);
    cursor: pointer;
    z-index: 999;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    border: 1px solid rgba(255, 255, 255, 0.5);
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 25px rgba(67, 97, 238, 0.45);
}

/* Info Box / About & Contact Pages */
.info-box {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 35px;
    box-shadow: 0 10px 30px rgba(67, 97, 238, 0.05);
}

.info-box h2 {
    color: var(--accent-blue);
    font-size: 1.6rem;
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.info-list {
    list-style: none;
    margin-top: 15px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.info-list li {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-primary);
}

.info-list i {
    color: var(--accent-light-blue);
    font-size: 1.1rem;
}

/* Footer */
footer {
    background: var(--bg-card);
    border-top: 1px solid var(--border-color);
    text-align: center;
    padding: 20px 5%;
    color: var(--text-secondary);
    font-size: 0.85rem;
    margin-top: auto;
}

/* Admin Dashboard Styling */
.admin-header {
    background: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
    padding: 15px 5%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 15px;
}

.admin-header h2 {
    font-size: 1.3rem;
    color: var(--accent-blue);
    display: flex;
    align-items: center;
    gap: 10px;
}

.admin-actions {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.btn {
    padding: 9px 18px;
    border-radius: 8px;
    font-weight: 600;
    font-size: 0.88rem;
    border: none;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    transition: all 0.2s ease;
}

.btn-add { background: var(--stock-green); color: #fff; }
.btn-home { background: var(--accent-blue); color: #fff; }
.btn-logout { background: var(--out-red); color: #fff; }

.btn:hover { opacity: 0.9; transform: translateY(-2px); }

.table-responsive {
    width: 100%;
    overflow-x: auto;
    margin-top: 20px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    background: var(--bg-card);
}

.admin-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--bg-card);
    text-align: left;
    white-space: nowrap;
}

.admin-table th {
    background: #f1f5f9;
    color: var(--accent-blue);
    padding: 14px;
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    border-bottom: 1px solid var(--border-color);
}

.admin-table td {
    padding: 12px 14px;
    border-bottom: 1px solid var(--border-color);
    font-size: 0.9rem;
}

.admin-table tr:hover {
    background: rgba(67, 97, 238, 0.04);
}

.form-card {
    max-width: 520px;
    margin: 40px auto;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 30px;
    border-radius: 16px;
    box-shadow: 0 10px 30px rgba(67, 97, 238, 0.08);
}

.form-card h3 {
    color: var(--accent-blue);
    font-size: 1.3rem;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.form-group {
    margin-bottom: 18px;
}

.form-group label {
    display: block;
    font-size: 0.88rem;
    color: var(--text-secondary);
    margin-bottom: 6px;
}

.form-group input, .form-group select {
    width: 100%;
    padding: 11px 14px;
    background: #f8fafc;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 0.92rem;
    outline: none;
}

.form-group input:focus, .form-group select:focus {
    border-color: var(--accent-light-blue);
    background: #ffffff;
    box-shadow: 0 0 10px var(--shadow-blue);
}