/* ===========================================
   东方墨韵 — Editorial Chinese Ink
   暗色基底 × 水墨质感 × 编辑排版
   =========================================== */

@import url('https://fonts.googleapis.com/css2?family=LXGW+WenKai:wght@400;700&family=Fraunces:opsz,wght@9..144,400;9..144,600;9..144,700&family=Noto+Sans+SC:wght@400;500;700&family=Noto+Serif+SC:wght@400;600;700&display=swap');

:root {
    --bg-ink: #111010;
    --bg-paper: #1A1816;
    --bg-panel: #22201D;
    --bg-elevated: #2A2825;
    --bg-hover: #33302D;

    --text-primary: #F0EBE1;
    --text-secondary: #B5ADA2;
    --text-tertiary: #7D7568;
    --text-muted: #5A554D;

    --accent: #C4463A;
    --accent-hover: #D4574B;
    --accent-soft: rgba(196,70,58,0.12);
    --accent-glow: rgba(196,70,58,0.25);

    --gold: #C4A35A;
    --gold-soft: rgba(196,163,90,0.12);

    --border: rgba(240,235,225,0.07);
    --border-strong: rgba(240,235,225,0.14);
    --border-accent: rgba(196,70,58,0.25);

    --shadow-sm: 0 1px 3px rgba(0,0,0,0.4);
    --shadow-md: 0 4px 20px rgba(0,0,0,0.5);
    --shadow-lg: 0 12px 48px rgba(0,0,0,0.6);

    --font-display: 'LXGW WenKai','Noto Serif SC',serif;
    --font-display-en: 'Fraunces','Georgia',serif;
    --font-body: 'Noto Sans SC',-apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif;
    --font-mono: 'Courier New',monospace;

    --space-xs: 8px;
    --space-sm: 16px;
    --space-md: 24px;
    --space-lg: 40px;
    --space-xl: 64px;
    --space-2xl: 96px;
    --space-3xl: 140px;

    --radius-sm: 2px;
    --radius-md: 4px;
    --radius-lg: 6px;
    --radius-xl: 8px;
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    scrollbar-gutter: stable;
}

body {
    font-family: var(--font-body);
    background: var(--bg-ink);
    color: var(--text-primary);
    line-height: 1.7;
    overflow-x: hidden;
    position: relative;
}

/* FOUC prevention: hide bilingual text until language.js applies the correct locale */
[data-zh][data-en] { visibility: hidden; }
body.lang-ready [data-zh][data-en] { visibility: visible; }

body::before {
    content: '';
    position: fixed;
    inset: 0;
    background:
        url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.03'/%3E%3C/svg%3E");
    pointer-events: none;
    z-index: 999;
}

a { color: inherit; text-decoration: none; transition: color 0.3s ease; }
img { max-width: 100%; display: block; }
ul, ol { list-style: none; }

h1,h2,h3,h4,h5,h6 {
    font-family: var(--font-display);
    font-weight: 700;
    line-height: 1.3;
    letter-spacing: 0.02em;
}

/* ========= 导航 ========= */
header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(17,16,16,0.85);
    backdrop-filter: blur(16px) saturate(1.2);
    -webkit-backdrop-filter: blur(16px) saturate(1.2);
    border-bottom: 1px solid var(--border);
}

.main-nav { height: 64px; }

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-md);
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo a {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo img {
    height: 28px;
    width: auto;
    filter: brightness(1.1);
}

.logo-brand {
    font-family: var(--font-display);
    font-size: 20px;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: 0.08em;
}

.nav-links {
    display: flex;
    gap: 6px;
}

.nav-links a {
    padding: 6px 14px;
    min-width: 72px;
    text-align: center;
    font-size: 14px;
    color: var(--text-secondary);
    border-radius: var(--radius-md);
    transition: color 0.3s ease, background 0.3s ease;
    position: relative;
}

.nav-links a:hover { color: var(--text-primary); background: var(--bg-hover); }

.nav-links a.active {
    color: var(--accent);
    background: var(--accent-soft);
}

.nav-links a.active::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 50%;
    transform: translateX(-50%);
    width: 16px;
    height: 2px;
    background: var(--accent);
    border-radius: 1px;
}

.nav-right { display: flex; align-items: center; }

.language-switch { position: relative; }

.dropdown-trigger {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    font-size: 13px;
    color: var(--text-tertiary);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: color 0.3s ease, border-color 0.3s ease;
}

.dropdown-trigger:hover {
    color: var(--text-secondary);
    border-color: var(--border-strong);
}

.dropdown-content {
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    min-width: 140px;
    background: var(--bg-elevated);
    border: 1px solid var(--border-strong);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-4px);
    transition: opacity 0.25s ease, visibility 0.25s ease, transform 0.25s ease;
    z-index: 100;
}

.dropdown:hover .dropdown-content {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-content a {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 16px;
    font-size: 13px;
    color: var(--text-secondary);
    transition: background 0.2s ease, color 0.2s ease;
}

.dropdown-content a:hover { background: var(--bg-hover); color: var(--text-primary); }
.dropdown-content a.active { color: var(--accent); }

.lang-code {
    font-size: 11px;
    color: var(--text-muted);
    font-family: var(--font-mono);
}

/* ========= 通用按钮 ========= */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 11px 24px;
    font-size: 14px;
    font-weight: 500;
    font-family: var(--font-body);
    border-radius: var(--radius-md);
    border: 1px solid transparent;
    cursor: pointer;
    transition: all 0.35s ease;
    white-space: nowrap;
}

.btn i { font-size: 12px; transition: transform 0.3s ease; }
.btn:hover i { transform: translateX(3px); }

.btn-primary {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
    box-shadow: 0 2px 12px var(--accent-glow);
}

.btn-primary:hover {
    background: var(--accent-hover);
    border-color: var(--accent-hover);
    box-shadow: 0 4px 24px var(--accent-glow);
    transform: translateY(-1px);
}

.btn-secondary {
    background: transparent;
    color: var(--text-secondary);
    border-color: var(--border-strong);
}

.btn-secondary:hover {
    color: var(--text-primary);
    border-color: var(--text-tertiary);
    background: var(--bg-hover);
}

.btn-large { padding: 14px 32px; font-size: 15px; }

/* ========= 页面面包屑 ========= */
.page-breadcrumb {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 13px;
    color: var(--text-muted);
    margin-bottom: var(--space-md);
}

.page-breadcrumb a { color: var(--text-tertiary); }
.page-breadcrumb a:hover { color: var(--accent); }
.page-breadcrumb i { font-size: 9px; }

/* ========= 墨线分隔 ========= */
.ink-divider {
    width: 100%;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--border-strong) 30%, var(--border-strong) 70%, transparent);
    margin: var(--space-xl) 0;
}

.ink-dot-divider {
    display: flex;
    justify-content: center;
    gap: 12px;
    padding: var(--space-lg) 0;
}

.ink-dot-divider::before,
.ink-dot-divider::after {
    content: '·';
    color: var(--text-muted);
    font-size: 20px;
}

/* ========= 章节标题 ========= */
.section-eyebrow {
    font-family: var(--font-display);
    font-size: 13px;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 12px;
}

.section-title {
    font-family: var(--font-display);
    font-size: clamp(28px, 3.5vw, 40px);
    color: var(--text-primary);
    margin-bottom: 16px;
    position: relative;
}

.section-description {
    font-size: 16px;
    color: var(--text-secondary);
    max-width: 560px;
    line-height: 1.8;
}

/* ========= 页脚 ========= */
footer {
    background: var(--bg-ink);
    border-top: 1px solid var(--border);
    padding: var(--space-2xl) 0 var(--space-lg);
    position: relative;
}

footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 1px;
    background: var(--accent);
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-md);
}

.footer-main {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: var(--space-xl);
    padding-bottom: var(--space-xl);
    border-bottom: 1px solid var(--border);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: var(--space-sm);
}

.footer-logo img { height: 24px; filter: brightness(1.1); }

.footer-logo-text {
    font-family: var(--font-display);
    font-size: 18px;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: 0.08em;
}

.footer-description {
    font-size: 14px;
    color: var(--text-tertiary);
    line-height: 1.8;
    max-width: 280px;
}

.footer-group-title {
    font-family: var(--font-display);
    font-size: 12px;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--text-muted);
    margin-bottom: var(--space-md);
    padding-bottom: 10px;
    border-bottom: 1px solid var(--border);
}

.footer-links-list { display: flex; flex-direction: column; gap: 10px; }

.footer-links-list a {
    font-size: 14px;
    color: var(--text-tertiary);
    transition: color 0.3s ease;
}

.footer-links-list a:hover { color: var(--accent); }

.footer-contact-item {
    font-size: 13px;
    color: var(--text-tertiary);
    line-height: 1.6;
}

.footer-contact-item strong {
    color: var(--text-muted);
    font-weight: 500;
    font-size: 12px;
    letter-spacing: 0.05em;
}

.footer-bottom {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: var(--space-lg);
}

.footer-copyright p {
    font-size: 12px;
    color: var(--text-muted);
}

.footer-social {
    display: flex;
    gap: 12px;
}

.footer-social-link {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    color: var(--text-muted);
    font-size: 15px;
    transition: all 0.3s ease;
}

.footer-social-link:hover {
    color: var(--accent);
    border-color: var(--border-accent);
    background: var(--accent-soft);
}

/* ========= 响应式 ========= */
@media (max-width: 900px) {
    .nav-links { display: none; }
    .footer-main { grid-template-columns: 1fr 1fr; gap: var(--space-lg); }
}

@media (max-width: 600px) {
    .footer-main { grid-template-columns: 1fr; gap: var(--space-lg); }
    .footer-bottom { flex-direction: column; gap: var(--space-sm); text-align: center; }
}