/* ============================================
   海角社区 - 全站样式表
   品牌：海角社区 | 域名：ec918.cn
   定位：国内影视传媒公司+视频社区
   ============================================ */

/* CSS Variables */
:root {
    --primary: #1a1a2e;
    --secondary: #e94560;
    --accent: #0f3460;
    --dark: #16213e;
    --text-light: #eaeaea;
    --text-muted: #a0a0b8;
    --bg-dark: #0a0a1a;
    --bg-card: #12122a;
    --bg-card-hover: #1a1a3e;
    --gradient-primary: linear-gradient(135deg, #e94560, #ff6b6b);
    --gradient-accent: linear-gradient(135deg, #0f3460, #1a1a2e);
    --gradient-hero: linear-gradient(180deg, rgba(10,10,26,0.3) 0%, rgba(10,10,26,0.85) 100%);
    --border-color: rgba(233,69,96,0.15);
    --shadow-card: 0 4px 24px rgba(0,0,0,0.3);
    --shadow-hover: 0 8px 40px rgba(233,69,96,0.2);
    --radius: 12px;
    --radius-sm: 8px;
    --radius-lg: 20px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --max-width: 1280px;
    --font-main: 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
}

/* Reset & Base */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
    font-family: var(--font-main);
    background: var(--bg-dark);
    color: var(--text-light);
    line-height: 1.7;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}
a { color: var(--secondary); text-decoration: none; transition: var(--transition); }
a:hover { color: #ff6b6b; }
img { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }
h1, h2, h3, h4, h5, h6 { font-weight: 700; line-height: 1.3; color: var(--text-light); }

/* Container */
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 20px; }
.section-padding { padding: 80px 0; }

/* ============================================
   Header & Navigation
   ============================================ */
.site-header {
    position: fixed; top: 0; left: 0; width: 100%; z-index: 1000;
    background: rgba(10,10,26,0.92); backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    transition: var(--transition);
}
.site-header.scrolled { background: rgba(10,10,26,0.98); box-shadow: 0 2px 20px rgba(0,0,0,0.5); }
.header-inner {
    display: flex; align-items: center; justify-content: space-between;
    max-width: var(--max-width); margin: 0 auto; padding: 0 20px; height: 70px;
}
.logo-wrap { display: flex; align-items: center; gap: 10px; }
.logo-wrap img { height: 42px; width: auto; }
.logo-text { font-size: 1.3rem; font-weight: 800; color: var(--text-light); letter-spacing: 1px; }
.logo-text span { color: var(--secondary); }

/* Main Nav */
.main-nav { display: flex; align-items: center; gap: 6px; }
.main-nav a {
    color: var(--text-muted); font-size: 0.92rem; padding: 8px 14px;
    border-radius: var(--radius-sm); transition: var(--transition); font-weight: 500;
    white-space: nowrap;
}
.main-nav a:hover, .main-nav a.active { color: var(--text-light); background: rgba(233,69,96,0.12); }
.nav-toggle { display: none; flex-direction: column; gap: 5px; cursor: pointer; padding: 8px; }
.nav-toggle span { display: block; width: 24px; height: 2px; background: var(--text-light); transition: var(--transition); border-radius: 2px; }

/* Search Bar */
.search-bar-wrap {
    background: var(--primary); border-bottom: 1px solid var(--border-color);
    padding: 12px 0; margin-top: 70px;
}
.search-bar {
    max-width: 680px; margin: 0 auto; display: flex; gap: 0;
    background: var(--bg-card); border-radius: 50px; overflow: hidden;
    border: 1px solid var(--border-color);
}
.search-bar input {
    flex: 1; padding: 12px 24px; background: transparent; border: none;
    color: var(--text-light); font-size: 0.95rem; outline: none;
    font-family: var(--font-main);
}
.search-bar input::placeholder { color: var(--text-muted); }
.search-bar button {
    padding: 12px 28px; background: var(--gradient-primary); border: none;
    color: #fff; font-size: 0.95rem; cursor: pointer; font-weight: 600;
    transition: var(--transition); font-family: var(--font-main);
}
.search-bar button:hover { opacity: 0.9; }

/* ============================================
   Hero Section
   ============================================ */
.hero-section {
    position: relative; min-height: 560px; display: flex; align-items: center;
    overflow: hidden; background: var(--bg-dark);
}
.hero-bg {
    position: absolute; inset: 0; background-size: cover; background-position: center;
    z-index: 1;
}
.hero-bg::after {
    content: ''; position: absolute; inset: 0;
    background: var(--gradient-hero); z-index: 2;
}
.hero-content {
    position: relative; z-index: 3; max-width: var(--max-width);
    margin: 0 auto; padding: 0 20px; text-align: center; width: 100%;
}
.hero-badge {
    display: inline-block; padding: 6px 20px; background: rgba(233,69,96,0.15);
    border: 1px solid rgba(233,69,96,0.3); border-radius: 50px;
    font-size: 0.85rem; color: var(--secondary); margin-bottom: 20px; font-weight: 500;
}
.hero-title { font-size: 3rem; font-weight: 900; margin-bottom: 16px; letter-spacing: 2px; }
.hero-title span { background: var(--gradient-primary); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.hero-subtitle { font-size: 1.15rem; color: var(--text-muted); max-width: 640px; margin: 0 auto 30px; line-height: 1.8; }
.hero-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn {
    display: inline-flex; align-items: center; gap: 8px; padding: 13px 32px;
    border-radius: 50px; font-size: 0.95rem; font-weight: 600; cursor: pointer;
    transition: var(--transition); border: none; font-family: var(--font-main);
}
.btn-primary { background: var(--gradient-primary); color: #fff; }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 30px rgba(233,69,96,0.4); color: #fff; }
.btn-outline {
    background: transparent; color: var(--text-light);
    border: 2px solid rgba(255,255,255,0.25);
}
.btn-outline:hover { border-color: var(--secondary); color: var(--secondary); }
.hero-stats {
    display: flex; justify-content: center; gap: 50px; margin-top: 50px;
    padding-top: 30px; border-top: 1px solid rgba(255,255,255,0.08);
}
.hero-stat-item { text-align: center; }
.hero-stat-num { font-size: 2rem; font-weight: 800; color: var(--secondary); }
.hero-stat-label { font-size: 0.85rem; color: var(--text-muted); margin-top: 4px; }

/* ============================================
   Section Titles
   ============================================ */
.section-header { text-align: center; margin-bottom: 50px; }
.section-tag {
    display: inline-block; padding: 4px 16px; background: rgba(233,69,96,0.1);
    border-radius: 50px; font-size: 0.82rem; color: var(--secondary);
    margin-bottom: 12px; font-weight: 500; letter-spacing: 1px; text-transform: uppercase;
}
.section-title { font-size: 2.2rem; font-weight: 800; margin-bottom: 12px; }
.section-title span { color: var(--secondary); }
.section-desc { font-size: 1rem; color: var(--text-muted); max-width: 600px; margin: 0 auto; }

/* ============================================
   Video Cards
   ============================================ */
.video-grid {
    display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 24px;
}
.video-card {
    background: var(--bg-card); border-radius: var(--radius); overflow: hidden;
    border: 1px solid var(--border-color); transition: var(--transition);
    cursor: pointer;
}
.video-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); border-color: rgba(233,69,96,0.3); }
.video-thumb {
    position: relative; padding-top: 56.25%; overflow: hidden;
}
.video-thumb img {
    position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover;
    transition: transform 0.5s ease;
}
.video-card:hover .video-thumb img { transform: scale(1.05); }
.video-play-btn {
    position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%);
    width: 60px; height: 60px; background: rgba(233,69,96,0.9); border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
    opacity: 0; transition: var(--transition); z-index: 5;
}
.video-play-btn::after {
    content: ''; width: 0; height: 0; border-style: solid;
    border-width: 10px 0 10px 18px; border-color: transparent transparent transparent #fff;
    margin-left: 3px;
}
.video-card:hover .video-play-btn { opacity: 1; }
.video-duration {
    position: absolute; bottom: 10px; right: 10px; background: rgba(0,0,0,0.8);
    color: #fff; padding: 2px 8px; border-radius: 4px; font-size: 0.8rem; z-index: 5;
}
.video-info { padding: 16px; }
.video-title { font-size: 1rem; font-weight: 600; margin-bottom: 8px; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.video-meta { display: flex; align-items: center; gap: 16px; font-size: 0.82rem; color: var(--text-muted); flex-wrap: wrap; }
.video-meta-item { display: flex; align-items: center; gap: 4px; }
.video-tags { display: flex; gap: 6px; margin-top: 10px; flex-wrap: wrap; }
.video-tag {
    padding: 2px 10px; background: rgba(233,69,96,0.1); border-radius: 50px;
    font-size: 0.75rem; color: var(--secondary);
}

/* ============================================
   Feature Cards
   ============================================ */
.feature-grid {
    display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
}
.feature-card {
    background: var(--bg-card); border-radius: var(--radius); padding: 32px 24px;
    border: 1px solid var(--border-color); transition: var(--transition);
    text-align: center;
}
.feature-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); border-color: rgba(233,69,96,0.3); }
.feature-icon {
    width: 64px; height: 64px; margin: 0 auto 20px; border-radius: 16px;
    background: var(--gradient-primary); display: flex; align-items: center;
    justify-content: center; font-size: 1.8rem;
}
.feature-title { font-size: 1.15rem; font-weight: 700; margin-bottom: 10px; }
.feature-desc { font-size: 0.9rem; color: var(--text-muted); line-height: 1.7; }

/* ============================================
   Expert Cards
   ============================================ */
.expert-grid {
    display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
}
.expert-card {
    background: var(--bg-card); border-radius: var(--radius); overflow: hidden;
    border: 1px solid var(--border-color); transition: var(--transition);
    text-align: center; padding: 32px 20px;
}
.expert-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }
.expert-avatar {
    width: 100px; height: 100px; border-radius: 50%; margin: 0 auto 16px;
    overflow: hidden; border: 3px solid var(--secondary);
}
.expert-avatar img { width: 100%; height: 100%; object-fit: cover; }
.expert-name { font-size: 1.1rem; font-weight: 700; margin-bottom: 4px; }
.expert-role { font-size: 0.85rem; color: var(--secondary); margin-bottom: 12px; }
.expert-bio { font-size: 0.88rem; color: var(--text-muted); margin-bottom: 16px; line-height: 1.6; }
.expert-actions { display: flex; gap: 10px; justify-content: center; }
.btn-sm { padding: 8px 18px; font-size: 0.82rem; border-radius: 50px; }

/* ============================================
   Brand Wall
   ============================================ */
.brand-wall {
    display: flex; flex-wrap: wrap; justify-content: center; gap: 30px;
    align-items: center; padding: 30px 0;
}
.brand-item {
    padding: 16px 28px; background: var(--bg-card); border-radius: var(--radius-sm);
    border: 1px solid var(--border-color); font-size: 1rem; font-weight: 600;
    color: var(--text-muted); transition: var(--transition);
}
.brand-item:hover { border-color: var(--secondary); color: var(--text-light); }

/* ============================================
   Reviews
   ============================================ */
.review-grid {
    display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 24px;
}
.review-card {
    background: var(--bg-card); border-radius: var(--radius); padding: 28px;
    border: 1px solid var(--border-color); transition: var(--transition);
}
.review-card:hover { border-color: rgba(233,69,96,0.3); }
.review-stars { color: #ffc107; font-size: 1rem; margin-bottom: 12px; letter-spacing: 2px; }
.review-text { font-size: 0.92rem; color: var(--text-muted); line-height: 1.7; margin-bottom: 16px; font-style: italic; }
.review-author { display: flex; align-items: center; gap: 12px; }
.review-author-avatar {
    width: 40px; height: 40px; border-radius: 50%; background: var(--gradient-primary);
    display: flex; align-items: center; justify-content: center; font-size: 0.9rem;
    font-weight: 700; color: #fff;
}
.review-author-info { }
.review-author-name { font-size: 0.9rem; font-weight: 600; }
.review-author-title { font-size: 0.8rem; color: var(--text-muted); }

/* ============================================
   FAQ Section
   ============================================ */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
    background: var(--bg-card); border-radius: var(--radius-sm); margin-bottom: 12px;
    border: 1px solid var(--border-color); overflow: hidden;
}
.faq-question {
    padding: 18px 24px; cursor: pointer; display: flex; justify-content: space-between;
    align-items: center; font-weight: 600; font-size: 0.95rem; transition: var(--transition);
}
.faq-question:hover { color: var(--secondary); }
.faq-arrow { transition: transform 0.3s ease; font-size: 1.2rem; color: var(--secondary); }
.faq-item.active .faq-arrow { transform: rotate(180deg); }
.faq-answer {
    max-height: 0; overflow: hidden; transition: max-height 0.4s ease;
    padding: 0 24px;
}
.faq-item.active .faq-answer { max-height: 300px; padding: 0 24px 18px; }
.faq-answer p { font-size: 0.9rem; color: var(--text-muted); line-height: 1.7; }

/* ============================================
   Contact Section
   ============================================ */
.contact-grid {
    display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 24px;
}
.contact-card {
    background: var(--bg-card); border-radius: var(--radius); padding: 28px;
    border: 1px solid var(--border-color); text-align: center;
}
.contact-icon { font-size: 2rem; margin-bottom: 12px; }
.contact-label { font-size: 0.85rem; color: var(--text-muted); margin-bottom: 6px; }
.contact-value { font-size: 1rem; font-weight: 600; }

/* ============================================
   QR Code Section
   ============================================ */
.qr-grid { display: flex; justify-content: center; gap: 40px; flex-wrap: wrap; }
.qr-item { text-align: center; }
.qr-item img { width: 180px; height: 180px; border-radius: var(--radius-sm); margin-bottom: 10px; }
.qr-label { font-size: 0.9rem; color: var(--text-muted); }

/* ============================================
   How-To Guide
   ============================================ */
.howto-steps {
    display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 24px; counter-reset: step;
}
.howto-step {
    background: var(--bg-card); border-radius: var(--radius); padding: 28px;
    border: 1px solid var(--border-color); position: relative; counter-increment: step;
}
.howto-step::before {
    content: counter(step); position: absolute; top: -12px; left: 20px;
    width: 32px; height: 32px; background: var(--gradient-primary); border-radius: 50%;
    display: flex; align-items: center; justify-content: center; font-weight: 700;
    font-size: 0.9rem; color: #fff;
}
.howto-step h4 { font-size: 1rem; margin-bottom: 8px; margin-top: 8px; }
.howto-step p { font-size: 0.88rem; color: var(--text-muted); }

/* ============================================
   Social Share
   ============================================ */
.share-buttons { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.share-btn {
    padding: 10px 20px; border-radius: 50px; font-size: 0.88rem; font-weight: 600;
    border: 1px solid var(--border-color); background: var(--bg-card);
    color: var(--text-light); cursor: pointer; transition: var(--transition);
}
.share-btn:hover { border-color: var(--secondary); color: var(--secondary); }

/* ============================================
   Gallery Section
   ============================================ */
.gallery-grid {
    display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 16px;
}
.gallery-item {
    border-radius: var(--radius); overflow: hidden; position: relative;
    aspect-ratio: 3/4; cursor: pointer;
}
.gallery-item img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s ease; }
.gallery-item:hover img { transform: scale(1.08); }
.gallery-overlay {
    position: absolute; inset: 0; background: linear-gradient(to top, rgba(0,0,0,0.7) 0%, transparent 50%);
    display: flex; align-items: flex-end; padding: 16px; opacity: 0; transition: var(--transition);
}
.gallery-item:hover .gallery-overlay { opacity: 1; }
.gallery-overlay span { color: #fff; font-size: 0.9rem; font-weight: 600; }

/* ============================================
   Footer
   ============================================ */
.site-footer {
    background: var(--primary); border-top: 1px solid var(--border-color);
    padding: 60px 0 0;
}
.footer-grid {
    display: grid; grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px; margin-bottom: 40px;
}
.footer-brand p { font-size: 0.88rem; color: var(--text-muted); margin-top: 12px; line-height: 1.7; }
.footer-title { font-size: 1rem; font-weight: 700; margin-bottom: 16px; color: var(--text-light); }
.footer-links a { display: block; color: var(--text-muted); font-size: 0.88rem; padding: 4px 0; }
.footer-links a:hover { color: var(--secondary); }
.footer-bottom {
    border-top: 1px solid var(--border-color); padding: 20px 0;
    text-align: center; font-size: 0.85rem; color: var(--text-muted);
}
.footer-bottom a { color: var(--secondary); }

/* ============================================
   Breadcrumb
   ============================================ */
.breadcrumb {
    padding: 16px 0; font-size: 0.85rem; color: var(--text-muted);
    margin-top: 70px;
}
.breadcrumb a { color: var(--text-muted); }
.breadcrumb a:hover { color: var(--secondary); }
.breadcrumb span { margin: 0 8px; }

/* ============================================
   Inner Page Content
   ============================================ */
.page-hero {
    background: var(--primary); padding: 80px 0 40px; text-align: center;
    margin-top: 70px;
}
.page-hero h1 { font-size: 2.4rem; margin-bottom: 12px; }
.page-hero p { font-size: 1rem; color: var(--text-muted); }
.content-section { padding: 60px 0; }
.content-section p { font-size: 0.95rem; color: var(--text-muted); line-height: 1.8; margin-bottom: 16px; }
.content-section h2 { font-size: 1.6rem; margin-bottom: 16px; }
.content-section h3 { font-size: 1.3rem; margin-bottom: 12px; }

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 1024px) {
    .footer-grid { grid-template-columns: 1fr 1fr; }
    .hero-title { font-size: 2.4rem; }
    .hero-stats { gap: 30px; }
}

@media (max-width: 768px) {
    .main-nav {
        display: none; position: fixed; top: 70px; left: 0; width: 100%;
        background: rgba(10,10,26,0.98); flex-direction: column; padding: 20px;
        gap: 4px; border-bottom: 1px solid var(--border-color);
    }
    .main-nav.active { display: flex; }
    .nav-toggle { display: flex; }
    .hero-section { min-height: 480px; }
    .hero-title { font-size: 1.8rem; }
    .hero-subtitle { font-size: 1rem; }
    .hero-stats { flex-direction: column; gap: 16px; }
    .section-title { font-size: 1.6rem; }
    .section-padding { padding: 50px 0; }
    .video-grid { grid-template-columns: 1fr; }
    .feature-grid { grid-template-columns: 1fr; }
    .expert-grid { grid-template-columns: 1fr; }
    .review-grid { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr; gap: 24px; }
    .search-bar { margin: 0 16px; }
    .container { padding: 0 16px; }
}

@media (max-width: 480px) {
    .hero-title { font-size: 1.5rem; }
    .hero-actions { flex-direction: column; align-items: center; }
    .btn { width: 100%; justify-content: center; }
    .qr-grid { flex-direction: column; align-items: center; }
}

/* ============================================
   Animations
   ============================================ */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}
.animate-in { animation: fadeInUp 0.6s ease forwards; }

/* Lazy Load Placeholder */
.lazy-placeholder {
    background: var(--bg-card); display: flex; align-items: center; justify-content: center;
    color: var(--text-muted); font-size: 0.85rem;
}

/* MCP Frontend Placeholder */
.mcp-widget {
    background: var(--bg-card); border-radius: var(--radius); padding: 20px;
    border: 1px solid var(--border-color); text-align: center;
    font-size: 0.9rem; color: var(--text-muted);
}

/* Live indicator */
.live-badge {
    display: inline-flex; align-items: center; gap: 6px; padding: 3px 10px;
    background: rgba(233,69,96,0.15); border-radius: 50px; font-size: 0.75rem;
    color: var(--secondary); font-weight: 600;
}
.live-dot {
    width: 8px; height: 8px; background: var(--secondary); border-radius: 50%;
    animation: pulse 1.5s infinite;
}
@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.4; }
}

/* Scrollbar */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--bg-dark); }
::-webkit-scrollbar-thumb { background: var(--accent); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--secondary); }


/* ========== 视频模态播放器 ========== */
.video-modal {
    position: fixed; top: 0; left: 0; width: 100%; height: 100%;
    background: rgba(0,0,0,0.92); z-index: 10000; display: flex;
    align-items: center; justify-content: center; padding: 20px;
    animation: fadeIn 0.3s ease;
}
.video-modal-content {
    background: var(--bg-card); border-radius: var(--radius);
    max-width: 900px; width: 100%; overflow: hidden; position: relative;
}
.video-modal-close {
    position: absolute; top: 12px; right: 16px; font-size: 2rem;
    color: #fff; cursor: pointer; z-index: 10; width: 40px; height: 40px;
    display: flex; align-items: center; justify-content: center;
    background: rgba(0,0,0,0.5); border-radius: 50%;
    transition: background 0.2s;
}
.video-modal-close:hover { background: var(--secondary); }
.video-modal-player { position: relative; width: 100%; aspect-ratio: 16/9; background: #000; }
.video-modal-poster {
    width: 100%; height: 100%; background-size: cover; background-position: center;
    display: flex; flex-direction: column; align-items: center; justify-content: center;
}
.video-modal-play-icon {
    width: 80px; height: 80px; border-radius: 50%;
    background: rgba(233,69,96,0.85); position: relative;
}
.video-modal-play-icon::after {
    content: ''; position: absolute; top: 50%; left: 55%;
    transform: translate(-50%, -50%);
    border-style: solid; border-width: 15px 0 15px 26px;
    border-color: transparent transparent transparent #fff;
}
.video-modal-text {
    color: #fff; margin-top: 16px; font-size: 1rem;
    text-shadow: 0 2px 8px rgba(0,0,0,0.5);
}
.video-modal-info { padding: 16px 20px; }
.video-modal-info h3 { font-size: 1.1rem; margin-bottom: 6px; }
.video-modal-info p { color: var(--text-muted); font-size: 0.85rem; }

/* ========== 返回顶部按钮 ========== */
.back-to-top {
    position: fixed; bottom: 30px; right: 30px; width: 48px; height: 48px;
    background: var(--secondary); color: #fff; border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
    font-size: 1.2rem; cursor: pointer; z-index: 9000;
    opacity: 0; visibility: hidden; transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(233,69,96,0.4);
}
.back-to-top.visible { opacity: 1; visibility: visible; }
.back-to-top:hover { transform: translateY(-3px); background: var(--accent); }

/* ========== 面包屑导航 ========== */
.breadcrumb {
    display: flex; align-items: center; gap: 8px; font-size: 0.85rem;
    color: var(--text-muted); margin-bottom: 16px; flex-wrap: wrap;
}
.breadcrumb a { color: var(--secondary); text-decoration: none; }
.breadcrumb a:hover { text-decoration: underline; }
.breadcrumb span { color: var(--text-muted); }

/* ========== 内页Hero ========== */
.page-hero {
    padding: 120px 0 40px; background: var(--primary);
    border-bottom: 1px solid var(--border-color);
}
.page-hero h1 { font-size: 2rem; margin-bottom: 8px; }
.page-hero p { color: var(--text-muted); font-size: 1rem; }

/* ========== 内页内容区 ========== */
.content-section {
    padding: 50px 0;
}
.content-section h2 {
    font-size: 1.6rem; margin-bottom: 16px; margin-top: 30px;
}
.content-section h2:first-child { margin-top: 0; }
.content-section h3 { font-size: 1.3rem; margin-bottom: 12px; }
.content-section p {
    color: var(--text-muted); line-height: 1.8; margin-bottom: 16px;
}

/* ========== 动画 ========== */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* ========== 移动端补充 ========== */
@media (max-width: 768px) {
    .video-modal-content { max-width: 95%; }
    .back-to-top { bottom: 20px; right: 20px; width: 42px; height: 42px; }
    .page-hero { padding: 100px 0 30px; }
    .page-hero h1 { font-size: 1.5rem; }
    .content-section { padding: 30px 0; }
    .content-section h2 { font-size: 1.3rem; }
}