/* ============================================
   抖音风 - rdmprrns.cn 全站样式表 V2.0
   品牌色: 紫色 #6B21A8 / 青色 #0D9488 / 金色 #D4A843
   EEAT优化版 - 百度SEO最佳实践
   ============================================ */

/* CSS Reset & Base */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
    font-family: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', 'Noto Sans SC', sans-serif;
    color: #1a1a2e;
    background: #f8f6ff;
    line-height: 1.8;
    overflow-x: hidden;
}
a { color: #6B21A8; text-decoration: none; transition: color 0.3s; }
a:hover { color: #0D9488; }
img { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }
h1, h2, h3, h4, h5, h6 { font-weight: 700; line-height: 1.4; color: #1a1a2e; }

/* Container */
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.section { padding: 60px 0; }
.section-title {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 15px;
    color: #6B21A8;
    position: relative;
}
.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, #6B21A8, #0D9488);
    margin: 12px auto 0;
    border-radius: 2px;
}
.section-subtitle {
    text-align: center;
    color: #666;
    font-size: 1rem;
    margin-bottom: 40px;
}

/* Header / Navigation */
.site-header {
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 20px rgba(107, 33, 168, 0.3);
}
.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 20px;
    max-width: 1200px;
    margin: 0 auto;
    height: 64px;
}
.logo-wrap {
    display: flex;
    align-items: center;
    gap: 10px;
}
.logo-wrap img {
    height: 40px;
    width: 40px;
    border-radius: 8px;
}
.logo-wrap .brand-name {
    font-size: 1.3rem;
    font-weight: 800;
    background: linear-gradient(90deg, #D4A843, #0D9488);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.main-nav { display: flex; align-items: center; gap: 0; }
.main-nav a {
    color: #e0d6f0;
    padding: 20px 14px;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.3s;
    position: relative;
    white-space: nowrap;
}
.main-nav a:hover, .main-nav a.active {
    color: #D4A843;
}
.main-nav a::after {
    content: '';
    position: absolute;
    bottom: 15px;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background: #D4A843;
    transition: width 0.3s;
}
.main-nav a:hover::after, .main-nav a.active::after { width: 60%; }

/* Mobile Menu */
.menu-toggle {
    display: none;
    background: none;
    border: none;
    color: #D4A843;
    font-size: 1.5rem;
    cursor: pointer;
}

/* Search Bar */
.search-bar {
    background: linear-gradient(90deg, #6B21A8, #0D9488);
    padding: 12px 0;
}
.search-bar .container {
    display: flex;
    justify-content: center;
}
.search-box {
    display: flex;
    max-width: 600px;
    width: 100%;
    background: #fff;
    border-radius: 30px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0,0,0,0.15);
}
.search-box input {
    flex: 1;
    border: none;
    padding: 12px 24px;
    font-size: 0.95rem;
    outline: none;
    color: #333;
}
.search-box button {
    background: linear-gradient(135deg, #6B21A8, #0D9488);
    color: #fff;
    border: none;
    padding: 12px 28px;
    font-size: 0.95rem;
    cursor: pointer;
    font-weight: 600;
    transition: opacity 0.3s;
}
.search-box button:hover { opacity: 0.85; }

/* Hero Banner */
.hero-banner {
    position: relative;
    overflow: hidden;
    height: 480px;
}
.hero-banner img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}
.hero-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(26,26,46,0.85) 0%, rgba(107,33,168,0.5) 50%, rgba(13,148,136,0.3) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
}
.hero-content {
    text-align: center;
    color: #fff;
    max-width: 700px;
    padding: 0 20px;
}
.hero-content h1 {
    font-size: 2.8rem;
    color: #fff;
    margin-bottom: 15px;
    text-shadow: 0 2px 10px rgba(0,0,0,0.3);
}
.hero-content h1 .highlight {
    background: linear-gradient(90deg, #D4A843, #0D9488);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.hero-content p {
    font-size: 1.15rem;
    margin-bottom: 25px;
    opacity: 0.9;
}
.btn-primary {
    display: inline-block;
    background: linear-gradient(135deg, #6B21A8, #0D9488);
    color: #fff;
    padding: 12px 32px;
    border-radius: 30px;
    font-weight: 600;
    font-size: 1rem;
    transition: all 0.3s;
    box-shadow: 0 4px 15px rgba(107,33,168,0.4);
}
.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(107,33,168,0.5);
    color: #fff;
}
.btn-secondary {
    display: inline-block;
    background: transparent;
    color: #D4A843;
    border: 2px solid #D4A843;
    padding: 10px 28px;
    border-radius: 30px;
    font-weight: 600;
    font-size: 1rem;
    transition: all 0.3s;
    margin-left: 12px;
}
.btn-secondary:hover {
    background: #D4A843;
    color: #1a1a2e;
}

/* Video Grid */
.video-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}
.video-card {
    background: #fff;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0,0,0,0.08);
    transition: all 0.3s;
    cursor: pointer;
}
.video-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(107,33,168,0.2);
}
.video-card .thumb {
    position: relative;
    padding-top: 56.25%;
    overflow: hidden;
}
.video-card .thumb img {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s;
}
.video-card:hover .thumb img { transform: scale(1.05); }
.video-card .play-icon {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 50px;
    height: 50px;
    background: rgba(107,33,168,0.85);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.3s;
}
.video-card:hover .play-icon { opacity: 1; }
.play-icon::after {
    content: '';
    display: block;
    width: 0;
    height: 0;
    border-style: solid;
    border-width: 8px 0 8px 14px;
    border-color: transparent transparent transparent #fff;
    margin-left: 3px;
}
.video-card .card-body { padding: 14px 16px; }
.video-card .card-title {
    font-size: 0.95rem;
    font-weight: 600;
    margin-bottom: 8px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    line-height: 1.5;
}
.video-card .card-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.8rem;
    color: #888;
}
.video-card .tag {
    display: inline-block;
    background: linear-gradient(135deg, #f3e8ff, #e0f7f5);
    color: #6B21A8;
    padding: 2px 10px;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 500;
}
.video-card .views { color: #999; }

/* Video Badge - 视频标识 */
.video-badge {
    position: absolute;
    top: 10px;
    left: 10px;
    background: rgba(107,33,168,0.9);
    color: #fff;
    padding: 3px 10px;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 600;
    z-index: 2;
}
.video-duration {
    position: absolute;
    bottom: 8px;
    right: 8px;
    background: rgba(0,0,0,0.75);
    color: #fff;
    padding: 2px 8px;
    border-radius: 3px;
    font-size: 0.75rem;
    z-index: 2;
}

/* Category Tabs */
.tab-nav {
    display: flex;
    justify-content: center;
    gap: 12px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}
.tab-btn {
    background: #fff;
    border: 2px solid #e8e0f0;
    color: #6B21A8;
    padding: 8px 24px;
    border-radius: 25px;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
}
.tab-btn:hover, .tab-btn.active {
    background: linear-gradient(135deg, #6B21A8, #0D9488);
    color: #fff;
    border-color: transparent;
}

/* Expert Cards - EEAT增强 */
.expert-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}
.expert-card {
    background: #fff;
    border-radius: 16px;
    padding: 30px 20px;
    text-align: center;
    box-shadow: 0 4px 15px rgba(0,0,0,0.08);
    transition: all 0.3s;
}
.expert-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(107,33,168,0.15);
}
.expert-card .avatar {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    margin: 0 auto 15px;
    overflow: hidden;
    border: 3px solid #e8e0f0;
}
.expert-card .avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}
.expert-card h4 { font-size: 1.1rem; margin-bottom: 5px; }
.expert-card .role { color: #0D9488; font-size: 0.85rem; margin-bottom: 8px; }
.expert-card .credentials {
    font-size: 0.78rem;
    color: #888;
    margin-bottom: 10px;
    line-height: 1.6;
}
.expert-card .desc { color: #666; font-size: 0.85rem; margin-bottom: 15px; }
.expert-card .btn-sm {
    display: inline-block;
    background: linear-gradient(135deg, #6B21A8, #0D9488);
    color: #fff;
    padding: 6px 18px;
    border-radius: 20px;
    font-size: 0.8rem;
    margin: 0 4px;
    transition: opacity 0.3s;
}
.expert-card .btn-sm:hover { opacity: 0.85; color: #fff; }

/* Certification Badges - EEAT资质徽章 */
.cert-badges {
    display: flex;
    justify-content: center;
    gap: 30px;
    flex-wrap: wrap;
    margin-top: 30px;
    padding: 30px;
    background: linear-gradient(135deg, #f8f6ff, #f0fffe);
    border-radius: 16px;
}
.cert-badge {
    text-align: center;
    padding: 15px 20px;
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.06);
    min-width: 140px;
}
.cert-badge .badge-icon {
    font-size: 2rem;
    margin-bottom: 8px;
}
.cert-badge .badge-title {
    font-size: 0.85rem;
    font-weight: 600;
    color: #6B21A8;
    margin-bottom: 4px;
}
.cert-badge .badge-desc {
    font-size: 0.75rem;
    color: #888;
}

/* Case Studies - 案例展示 */
.case-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}
.case-card {
    background: #fff;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0,0,0,0.08);
    transition: all 0.3s;
}
.case-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(107,33,168,0.15);
}
.case-card .case-img {
    height: 180px;
    overflow: hidden;
}
.case-card .case-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s;
}
.case-card:hover .case-img img { transform: scale(1.05); }
.case-card .case-body {
    padding: 20px;
}
.case-card .case-body h4 {
    font-size: 1rem;
    margin-bottom: 8px;
    color: #1a1a2e;
}
.case-card .case-body p {
    font-size: 0.85rem;
    color: #666;
    margin-bottom: 10px;
}
.case-card .case-stats {
    display: flex;
    gap: 15px;
    font-size: 0.8rem;
    color: #0D9488;
}

/* Partners Grid - 合作品牌详细 */
.partners-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}
.partner-item {
    background: rgba(255,255,255,0.1);
    border: 1px solid rgba(212,168,67,0.2);
    border-radius: 12px;
    padding: 20px;
    text-align: center;
    transition: all 0.3s;
}
.partner-item:hover {
    background: rgba(255,255,255,0.15);
    border-color: #D4A843;
}
.partner-item .partner-name {
    color: #D4A843;
    font-weight: 600;
    font-size: 1rem;
    margin-bottom: 5px;
}
.partner-item .partner-type {
    color: #a0a0b0;
    font-size: 0.8rem;
}

/* FAQ Section */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
    background: #fff;
    border-radius: 12px;
    margin-bottom: 12px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    overflow: hidden;
}
.faq-question {
    padding: 18px 24px;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background 0.3s;
}
.faq-question:hover { background: #f8f6ff; }
.faq-question .icon {
    font-size: 1.2rem;
    color: #6B21A8;
    transition: transform 0.3s;
}
.faq-item.active .faq-question .icon { transform: rotate(45deg); }
.faq-answer {
    padding: 0 24px;
    max-height: 0;
    overflow: hidden;
    transition: all 0.3s ease;
    color: #555;
    line-height: 1.8;
}
.faq-item.active .faq-answer {
    padding: 0 24px 18px;
    max-height: 500px;
}

/* Reviews */
.review-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}
.review-card {
    background: #fff;
    border-radius: 12px;
    padding: 24px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.08);
    position: relative;
}
.review-card::before {
    content: '\201C';
    font-size: 3rem;
    color: #e8e0f0;
    position: absolute;
    top: 10px;
    left: 20px;
    font-family: serif;
}
.review-card .stars {
    color: #D4A843;
    margin-bottom: 10px;
    font-size: 0.9rem;
}
.review-card .text {
    color: #555;
    font-size: 0.9rem;
    margin-bottom: 15px;
    padding-top: 10px;
}
.review-card .author {
    display: flex;
    align-items: center;
    gap: 10px;
}
.review-card .author-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: linear-gradient(135deg, #6B21A8, #0D9488);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-weight: 700;
    font-size: 0.9rem;
}
.review-card .author-info .name { font-weight: 600; font-size: 0.9rem; }
.review-card .author-info .date { color: #999; font-size: 0.8rem; }

/* Partners Wall */
.partners-section { background: #1a1a2e; }
.partners-section .section-title { color: #D4A843; }
.partners-section .section-title::after { background: linear-gradient(90deg, #D4A843, #0D9488); }
.partners-section .section-subtitle { color: #a0a0b0; }
.partners-img {
    max-width: 900px;
    margin: 0 auto;
    border-radius: 12px;
    overflow: hidden;
}

/* Contact Section */
.contact-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}
.contact-info-card {
    background: #fff;
    border-radius: 16px;
    padding: 30px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.08);
}
.contact-info-card h3 {
    font-size: 1.3rem;
    color: #6B21A8;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid #f0e8ff;
}
.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    margin-bottom: 15px;
    font-size: 0.95rem;
}
.contact-item .label {
    font-weight: 600;
    color: #333;
    min-width: 80px;
}
.contact-item .value { color: #555; }
.qr-codes {
    display: flex;
    gap: 30px;
    justify-content: center;
    margin-top: 20px;
}
.qr-item { text-align: center; }
.qr-item img {
    width: 150px;
    height: 150px;
    border-radius: 8px;
    margin-bottom: 8px;
}
.qr-item .qr-label { font-size: 0.85rem; color: #666; }

/* How-To Guide */
.howto-steps {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    max-width: 1000px;
    margin: 0 auto;
}
.step-card {
    text-align: center;
    padding: 30px 20px;
    background: #fff;
    border-radius: 16px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.08);
    position: relative;
}
.step-num {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, #6B21A8, #0D9488);
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    font-weight: 800;
    margin: 0 auto 15px;
}
.step-card h4 { font-size: 1rem; margin-bottom: 8px; }
.step-card p { color: #666; font-size: 0.85rem; }

/* Social Share */
.share-bar {
    display: flex;
    justify-content: center;
    gap: 15px;
    padding: 20px 0;
}
.share-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 20px;
    border-radius: 25px;
    font-size: 0.85rem;
    font-weight: 500;
    color: #fff;
    transition: all 0.3s;
}
.share-btn:hover { transform: translateY(-2px); color: #fff; }
.share-btn.wechat { background: #07C160; }
.share-btn.weibo { background: #E6162D; }
.share-btn.douyin { background: #161823; }
.share-btn.bilibili { background: #00A1D6; }

/* Stats Counter - 数据统计 */
.stats-bar {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    padding: 40px 0;
}
.stat-item {
    text-align: center;
    padding: 25px 15px;
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.06);
}
.stat-num {
    font-size: 2.2rem;
    font-weight: 800;
    background: linear-gradient(135deg, #6B21A8, #0D9488);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 5px;
}
.stat-label {
    font-size: 0.9rem;
    color: #666;
}

/* Video Highlight Banner - 视频强调 */
.video-highlight {
    background: linear-gradient(135deg, #1a1a2e, #6B21A8);
    padding: 40px 0;
    text-align: center;
    color: #fff;
}
.video-highlight h2 {
    color: #D4A843;
    font-size: 1.8rem;
    margin-bottom: 15px;
}
.video-highlight p {
    color: #e0d6f0;
    max-width: 700px;
    margin: 0 auto 20px;
}
.video-highlight .video-tags {
    display: flex;
    justify-content: center;
    gap: 12px;
    flex-wrap: wrap;
}
.video-highlight .vtag {
    background: rgba(255,255,255,0.15);
    color: #D4A843;
    padding: 6px 18px;
    border-radius: 20px;
    font-size: 0.85rem;
    border: 1px solid rgba(212,168,67,0.3);
}

/* Footer */
.site-footer {
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    color: #a0a0b0;
    padding: 50px 0 0;
}
.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}
.footer-brand .footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 15px;
}
.footer-brand .footer-logo img { height: 36px; width: 36px; border-radius: 8px; }
.footer-brand .footer-logo span {
    font-size: 1.2rem;
    font-weight: 700;
    color: #D4A843;
}
.footer-brand p { font-size: 0.9rem; line-height: 1.8; margin-bottom: 15px; }
.footer-col h4 {
    color: #D4A843;
    font-size: 1rem;
    margin-bottom: 15px;
    padding-bottom: 8px;
    border-bottom: 1px solid rgba(212,168,67,0.2);
}
.footer-col a {
    display: block;
    color: #a0a0b0;
    font-size: 0.9rem;
    padding: 4px 0;
    transition: color 0.3s;
}
.footer-col a:hover { color: #D4A843; }
.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.1);
    padding: 20px 0;
    text-align: center;
    font-size: 0.85rem;
}
.footer-bottom .update-time { color: #888; margin-top: 5px; }
.footer-legal {
    margin-top: 10px;
    font-size: 0.8rem;
    color: #666;
}
.footer-legal a {
    color: #888;
    margin: 0 8px;
}
.footer-legal a:hover { color: #D4A843; }

/* Breadcrumb */
.breadcrumb {
    padding: 15px 0;
    font-size: 0.85rem;
    color: #888;
}
.breadcrumb a { color: #6B21A8; }
.breadcrumb span { margin: 0 8px; color: #ccc; }

/* Video Player Page */
.video-player-wrap {
    background: #000;
    border-radius: 12px;
    overflow: hidden;
    margin-bottom: 30px;
}
.video-player-wrap video {
    width: 100%;
    max-height: 600px;
}
.video-detail { padding: 20px 0; }
.video-detail h1 {
    font-size: 1.5rem;
    margin-bottom: 10px;
}
.video-detail .meta {
    display: flex;
    gap: 20px;
    color: #888;
    font-size: 0.9rem;
    margin-bottom: 20px;
    flex-wrap: wrap;
}
.video-detail .description {
    background: #fff;
    padding: 20px;
    border-radius: 12px;
    color: #555;
    line-height: 1.8;
}
.related-videos h3 {
    font-size: 1.2rem;
    margin-bottom: 20px;
    color: #6B21A8;
}

/* Category Page Banner */
.category-banner {
    height: 300px;
    position: relative;
    overflow: hidden;
}
.category-banner img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}
.category-banner .overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(26,26,46,0.8), rgba(107,33,168,0.5));
    display: flex;
    align-items: center;
    justify-content: center;
}
.category-banner h1 {
    color: #fff;
    font-size: 2.2rem;
    text-shadow: 0 2px 10px rgba(0,0,0,0.3);
}

/* Module Sections */
.module-card {
    background: #fff;
    border-radius: 16px;
    padding: 30px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.08);
    margin-bottom: 24px;
}
.module-card h3 {
    color: #6B21A8;
    font-size: 1.2rem;
    margin-bottom: 15px;
}
.module-card p {
    margin-bottom: 12px;
    color: #555;
    line-height: 1.8;
}
.feature-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}
.feature-item {
    text-align: center;
    padding: 25px 15px;
    background: linear-gradient(135deg, #f8f6ff, #f0fffe);
    border-radius: 12px;
    transition: all 0.3s;
}
.feature-item:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(107,33,168,0.1);
}
.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 12px;
}
.feature-item h4 { font-size: 1rem; margin-bottom: 8px; }
.feature-item p { color: #666; font-size: 0.85rem; }

/* Back to Top */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, #6B21A8, #0D9488);
    color: #fff;
    border: none;
    border-radius: 50%;
    font-size: 1.2rem;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 15px rgba(107,33,168,0.4);
    transition: all 0.3s;
    z-index: 999;
}
.back-to-top:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(107,33,168,0.5);
}
.back-to-top.visible {
    display: flex;
}

/* Timeline - 发展历程 */
.timeline {
    position: relative;
    max-width: 800px;
    margin: 30px auto 0;
    padding-left: 30px;
}
.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background: linear-gradient(180deg, #6B21A8, #0D9488);
    border-radius: 2px;
}
.timeline-item {
    position: relative;
    padding: 0 0 30px 30px;
}
.timeline-item::before {
    content: '';
    position: absolute;
    left: -7px;
    top: 5px;
    width: 16px;
    height: 16px;
    background: #6B21A8;
    border-radius: 50%;
    border: 3px solid #f8f6ff;
}
.timeline-item h4 {
    color: #6B21A8;
    font-size: 1rem;
    margin-bottom: 5px;
}
.timeline-item p {
    color: #666;
    font-size: 0.9rem;
}

/* Legal Pages - 隐私政策/用户协议 */
.legal-content {
    max-width: 800px;
    margin: 0 auto;
    background: #fff;
    border-radius: 16px;
    padding: 40px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.08);
}
.legal-content h2 {
    color: #6B21A8;
    font-size: 1.3rem;
    margin: 30px 0 15px;
    padding-bottom: 8px;
    border-bottom: 2px solid #f0e8ff;
}
.legal-content h2:first-child { margin-top: 0; }
.legal-content p {
    color: #555;
    margin-bottom: 12px;
    line-height: 1.8;
}
.legal-content ul {
    padding-left: 20px;
    margin-bottom: 15px;
}
.legal-content ul li {
    color: #555;
    margin-bottom: 8px;
    list-style: disc;
    line-height: 1.8;
}

/* 404 Page */
.error-page {
    text-align: center;
    padding: 80px 20px;
}
.error-page .error-code {
    font-size: 8rem;
    font-weight: 900;
    background: linear-gradient(135deg, #6B21A8, #0D9488);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1;
    margin-bottom: 20px;
}
.error-page h1 {
    font-size: 1.8rem;
    margin-bottom: 15px;
}
.error-page p {
    color: #666;
    margin-bottom: 30px;
    font-size: 1.1rem;
}

/* Lazy Load */
.lazy { opacity: 0; transition: opacity 0.5s; }
.lazy.loaded { opacity: 1; }

/* Internal Link Cards */
.internal-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin-top: 30px;
}
.internal-link-card {
    display: block;
    background: linear-gradient(135deg, #f8f6ff, #f0fffe);
    padding: 18px 20px;
    border-radius: 12px;
    border: 1px solid #e8e0f0;
    transition: all 0.3s;
    text-align: center;
}
.internal-link-card:hover {
    border-color: #6B21A8;
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(107,33,168,0.1);
}
.internal-link-card h5 {
    font-size: 0.95rem;
    color: #6B21A8;
    margin-bottom: 5px;
}
.internal-link-card p {
    font-size: 0.8rem;
    color: #888;
}

/* Responsive */
@media (max-width: 1024px) {
    .video-grid { grid-template-columns: repeat(3, 1fr); }
    .expert-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: repeat(2, 1fr); }
    .howto-steps { grid-template-columns: repeat(2, 1fr); }
    .case-grid { grid-template-columns: repeat(2, 1fr); }
    .partners-grid { grid-template-columns: repeat(2, 1fr); }
    .stats-bar { grid-template-columns: repeat(2, 1fr); }
    .internal-links { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
    .main-nav { display: none; }
    .main-nav.open {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: #1a1a2e;
        padding: 10px 0;
        box-shadow: 0 10px 30px rgba(0,0,0,0.3);
    }
    .main-nav.open a { padding: 12px 24px; }
    .menu-toggle { display: block; }
    .video-grid { grid-template-columns: repeat(2, 1fr); gap: 16px; }
    .review-grid { grid-template-columns: 1fr; }
    .contact-grid { grid-template-columns: 1fr; }
    .feature-grid { grid-template-columns: repeat(2, 1fr); }
    .hero-banner { height: 350px; }
    .hero-content h1 { font-size: 1.8rem; }
    .section-title { font-size: 1.5rem; }
    .footer-grid { grid-template-columns: 1fr; gap: 20px; }
    .share-bar { flex-wrap: wrap; }
    .cert-badges { gap: 15px; }
    .internal-links { grid-template-columns: 1fr; }
}
@media (max-width: 480px) {
    .video-grid { grid-template-columns: 1fr; }
    .expert-grid { grid-template-columns: 1fr; }
    .feature-grid { grid-template-columns: 1fr; }
    .howto-steps { grid-template-columns: 1fr; }
    .hero-banner { height: 280px; }
    .hero-content h1 { font-size: 1.5rem; }
    .qr-codes { flex-direction: column; align-items: center; }
    .case-grid { grid-template-columns: 1fr; }
    .partners-grid { grid-template-columns: 1fr; }
    .stats-bar { grid-template-columns: 1fr; }
    .legal-content { padding: 20px; }
}