:root {
    --ink: #1a1208;
    --paper: #f5f0e8;
    --cream: #ede8dc;
    --gold: #c9973a;
    --gold-light: #e8c97a;
    --rust: #b5451b;
    --sage: #4a6741;
    --muted: #7a6e5f;
    --rule: #c8bfad;
}

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

body {
    background: var(--paper);
    color: var(--ink);
    font-family: 'Noto Serif SC', serif;
    max-width: 760px;
    margin: 0 auto;
    padding: 56px 32px 48px;
    position: relative;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* 纸张纹理 */
body::before {
    content: '';
    position: fixed;
    inset: 0;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='300' height='300'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3CfeColorMatrix type='saturate' values='0'/%3E%3C/filter%3E%3Crect width='300' height='300' filter='url(%23n)' opacity='0.035'/%3E%3C/svg%3E");
    pointer-events: none;
    z-index: 999;
}

/* ── 报头 ── */
.masthead {
    text-align: center;
    padding-bottom: 32px;
    border-bottom: 3px double var(--rule);
    animation: fadeUp 0.5s ease both;
}

.masthead-eyebrow {
    font-family: 'JetBrains Mono', monospace;
    font-size: 10px;
    letter-spacing: 5px;
    text-transform: uppercase;
    color: var(--muted);
    margin-bottom: 16px;
}

.masthead h1 {
    font-family: 'Playfair Display', serif;
    font-size: 62px;
    font-weight: 700;
    letter-spacing: -2px;
    line-height: 1;
    color: var(--ink);
}

.masthead h1 .accent {
    color: var(--rust);
    font-style: italic;
}

.masthead-rule {
    width: 48px;
    height: 2px;
    background: var(--gold);
    margin: 20px auto 16px;
}

.masthead-meta {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 20px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 10px;
    color: var(--muted);
    letter-spacing: 1px;
}

.masthead-meta .dot {
    color: var(--gold);
    font-size: 8px;
}

/* ── 栏目导语 ── */
.intro {
    text-align: center;
    padding: 28px 0 24px;
    border-bottom: 1px solid var(--rule);
    animation: fadeUp 0.5s 0.1s ease both;
}

.intro p {
    font-size: 14px;
    line-height: 1.9;
    color: var(--muted);
    max-width: 480px;
    margin: 0 auto;
}

/* ── 分区标题 ── */
.section-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin: 36px 0 24px;
    animation: fadeUp 0.5s 0.15s ease both;
}

.section-header .rule {
    flex: 1;
    height: 1px;
    background: var(--rule);
}

.section-header h2 {
    font-family: 'JetBrains Mono', monospace;
    font-size: 10px;
    letter-spacing: 4px;
    text-transform: uppercase;
    color: var(--muted);
    white-space: nowrap;
}

/* ── 导航卡片网格 ── */
.nav-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    flex: 1;
}

/* ── 单张导航卡 ── */
.nav-card {
    display: block;
    text-decoration: none;
    color: inherit;
    background: var(--cream);
    border: 1px solid var(--rule);
    border-top: 4px solid var(--ink);
    padding: 32px 28px 28px;
    position: relative;
    overflow: hidden;
    transition: border-top-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
    animation: fadeUp 0.5s ease both;
    cursor: pointer;
}

.nav-card:nth-child(1) { animation-delay: 0.2s; }
.nav-card:nth-child(2) { animation-delay: 0.3s; }
.nav-card:nth-child(3) { animation-delay: 0.4s; }
.nav-card:nth-child(4) { animation-delay: 0.5s; }
.nav-card:nth-child(5) { animation-delay: 0.6s; }
.nav-card:nth-child(6) { animation-delay: 0.7s; }
.nav-card:nth-child(7) { animation-delay: 0.8s; }

.nav-card::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, transparent 70%, rgba(201, 151, 58, 0.06) 100%);
    pointer-events: none;
}

.nav-card:hover {
    border-top-color: var(--rust);
    box-shadow: 0 8px 32px rgba(26, 18, 8, 0.12);
    transform: translateY(-3px);
}

.nav-card-domain {
    background: linear-gradient(180deg, #efe7d7 0%, #e8ddca 100%);
    border-top-color: var(--sage);
}

.nav-card-domain::before {
    background: linear-gradient(135deg, transparent 62%, rgba(74, 103, 65, 0.12) 100%);
}

.nav-card-domain:hover {
    border-top-color: var(--gold);
}

/* 卡片角标 */
.card-badge {
    font-family: 'JetBrains Mono', monospace;
    font-size: 9px;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: var(--muted);
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.card-badge::before {
    content: '';
    display: inline-block;
    width: 20px;
    height: 1px;
    background: var(--rule);
}

/* 卡片图标 */
.card-icon {
    font-size: 36px;
    margin-bottom: 18px;
    display: block;
    line-height: 1;
    filter: grayscale(20%);
}

/* 卡片标题 */
.card-title {
    font-family: 'Playfair Display', serif;
    font-size: 28px;
    font-weight: 700;
    color: var(--ink);
    line-height: 1.2;
    margin-bottom: 12px;
    letter-spacing: -0.5px;
}

.nav-card:hover .card-title {
    color: var(--rust);
}

/* 卡片描述 */
.card-desc {
    font-size: 13px;
    line-height: 1.8;
    color: var(--muted);
    margin-bottom: 28px;
}

/* 卡片底部 */
.card-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 16px;
    border-top: 1px dashed var(--rule);
}

.card-action {
    font-family: 'JetBrains Mono', monospace;
    font-size: 10px;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: var(--ink);
    transition: color 0.2s ease;
}

.nav-card:hover .card-action {
    color: var(--rust);
}

.card-arrow {
    font-size: 18px;
    color: var(--rule);
    transition: color 0.2s ease, transform 0.2s ease;
}

.nav-card:hover .card-arrow {
    color: var(--rust);
    transform: translateX(4px);
}

/* ── 页脚 ── */
.footer {
    border-top: 3px double var(--rule);
    padding-top: 20px;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 20px;
    margin-top: 48px;
    animation: fadeUp 0.5s 0.4s ease both;
}

.footer-title {
    font-size: 13px;
    font-weight: 700;
    color: var(--ink);
}

.footer-sub {
    font-family: 'JetBrains Mono', monospace;
    font-size: 10px;
    color: var(--muted);
    margin-top: 4px;
    line-height: 1.7;
}

.footer-right {
    text-align: right;
}

.footer-date {
    font-family: 'JetBrains Mono', monospace;
    font-size: 11px;
    color: var(--muted);
}

/* ── 动画 ── */
@keyframes fadeUp {
    from {
        opacity: 0;
        transform: translateY(12px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ── 响应式 ── */
@media (max-width: 580px) {
    body {
        padding: 32px 18px 36px;
    }

    .masthead h1 {
        font-size: 42px;
    }

    .nav-grid {
        grid-template-columns: 1fr;
    }

    .footer {
        flex-direction: column;
    }

    .footer-right {
        text-align: left;
    }
}