/* ===== CSS cho Bảo Tàng A320 Family ===== */

:root {
    --dark: #0a0a12;
    --darker: #050508;
    --light: #f0f0f0;
    --accent: #00a8e8;
    --accent-gold: #c9a86a;
    --text-muted: #9ca3af;
    --card-bg: rgba(255, 255, 255, 0.05);
    --card-border: rgba(255, 255, 255, 0.1);
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Inter', sans-serif;
    background: var(--dark);
    color: var(--light);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ===== Header ===== */
header {
    background: linear-gradient(135deg, #0a0a12 0%, #1a1a2e 100%);
    padding: 60px 0;
    text-align: center;
    border-bottom: 1px solid var(--card-border);
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    background: linear-gradient(45deg, var(--accent), var(--accent-gold));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.subtitle {
    color: var(--text-muted);
    font-size: 1.1rem;
    font-weight: 300;
}

/* ===== Navigation ===== */
.navbar {
    background: var(--darker);
    padding: 12px 0;
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid var(--card-border);
}

.nav-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 8px;
    list-style: none;
    padding: 0 20px;
}

.nav-grid a {
    display: block;
    padding: 12px 16px;
    text-align: center;
    color: var(--light);
    text-decoration: none;
    border-radius: 6px;
    transition: var(--transition);
    font-weight: 500;
    border: 1px solid transparent;
}

.nav-grid a:hover {
    background: var(--card-bg);
    border-color: var(--accent);
    color: var(--accent);
}

/* ===== Sections ===== */
section {
    padding: 60px 0;
    border-bottom: 1px solid var(--card-border);
}

section:last-child {
    border-bottom: none;
}

.section-title {
    text-align: center;
    font-size: 2.2rem;
    margin-bottom: 40px;
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -12px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, var(--accent), var(--accent-gold));
}

/* ===== Masonry Grid ===== */
.masonry-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
    margin-top: 30px;
}

.masonry-item {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 10px;
    overflow: hidden;
    transition: var(--transition);
    position: relative;
}

.masonry-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 40px rgba(0, 168, 232, 0.15);
    border-color: var(--accent);
}

.masonry-item img {
    width: 100%;
    height: auto;
    display: block;
    object-fit: contain;
    background: rgba(0, 0, 0, 0.3);
}

.masonry-caption {
    padding: 12px 16px;
    font-size: 0.9rem;
    color: var(--text-muted);
}

.masonry-caption strong {
    color: var(--light);
    display: block;
    margin-bottom: 4px;
}

/* ===== Spec Table ===== */
.spec-table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
}

.spec-table th {
    background: var(--accent);
    color: var(--dark);
    padding: 12px 16px;
    text-align: center;
    font-weight: 600;
}

.spec-table th:first-child {
    background: var(--accent-gold);
}

.spec-table td {
    padding: 10px 16px;
    text-align: center;
    border-bottom: 1px solid var(--card-border);
}

.spec-table tbody tr:hover {
    background: var(--card-bg);
}

/* ===== Variant Cards ===== */
.variant-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 20px;
}

.variant-card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    padding: 24px;
    text-align: center;
    transition: var(--transition);
}

.variant-card:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: var(--accent);
    transform: translateY(-5px);
}

.variant-card .variant-name {
    font-size: 1.8rem;
    color: var(--accent);
    margin-bottom: 8px;
}

.variant-card .variant-spec {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin: 5px 0;
}

.variant-card .variant-highlight {
    color: var(--accent-gold);
    font-weight: 600;
}

/* ===== Timeline ===== */
.timeline {
    position: relative;
    padding: 20px 0;
}

.timeline::before {
    content: '';
    position: absolute;
    top: 0;
    bottom: 0;
    width: 3px;
    background: var(--accent);
    left: 50%;
    margin-left: -1.5px;
}

.timeline-item {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 10px;
    padding: 24px;
    margin-bottom: 24px;
    position: relative;
    max-width: 55%;
}

.timeline-item:nth-child(odd) {
    margin-left: auto;
}

.timeline-item::before {
    content: '';
    position: absolute;
    top: 24px;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--accent);
    border: 2px solid var(--dark);
}

.timeline-item:nth-child(odd)::before {
    right: -10px;
}

.timeline-item:nth-child(even)::before {
    left: -10px;
}

.timeline-year {
    color: var(--accent-gold);
    font-weight: 700;
    font-size: 1.2rem;
    margin-bottom: 8px;
}

/* ===== Feature Boxes ===== */
.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.feature-box {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 10px;
    padding: 24px;
    transition: var(--transition);
}

.feature-box:hover {
    border-color: var(--accent);
}

.feature-box h3 {
    color: var(--accent);
    margin-bottom: 12px;
    font-size: 1.2rem;
}

/* ===== Footer ===== */
footer {
    background: var(--darker);
    text-align: center;
    padding: 30px 0;
    color: var(--text-muted);
    font-size: 0.85rem;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
    .nav-grid {
        display: flex;
        overflow-x: auto;
        overflow-y: hidden;
        scroll-behavior: smooth;
        -webkit-overflow-scrolling: touch;
        padding: 8px 16px;
        gap: 10px;
    }
    .nav-grid::-webkit-scrollbar {
        height: 4px;
    }
    .nav-grid::-webkit-scrollbar-track {
        background: var(--darker);
    }
    .nav-grid::-webkit-scrollbar-thumb {
        background: var(--accent);
        border-radius: 2px;
    }
    .nav-grid li {
        flex: 0 0 auto;
    }
    .nav-grid a {
        padding: 10px 18px;
        font-size: 0.9rem;
        min-width: 120px;
        text-align: center;
    }
    .timeline::before {
        left: 20px;
    }
    .timeline-item {
        max-width: 100%;
        margin-left: 0 !important;
    }
    .timeline-item:nth-child(odd)::before,
    .timeline-item:nth-child(even)::before {
        left: -10px;
    }
    header h1 {
        font-size: 1.8rem;
    }
}

@media (max-width: 480px) {
    .nav-grid a {
        padding: 8px 14px;
        font-size: 0.85rem;
        min-width: 100px;
    }
}