/* 糖心 - 汽车改装视频社区 原创样式 */
:root {
  --brand-primary: #e8650a;
  --brand-secondary: #ff9b3d;
  --brand-dark: #0d1b2a;
  --brand-deeper: #070f18;
  --surface-1: #112240;
  --surface-2: #1a2f4e;
  --surface-3: #243b5c;
  --text-primary: #f0f4f8;
  --text-secondary: #8ba4c4;
  --text-muted: #5a7a9e;
  --border-color: #1e3a5f;
  --success: #2ecc71;
  --warning: #f39c12;
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --shadow-card: 0 4px 24px rgba(0,0,0,0.3);
  --shadow-hover: 0 8px 40px rgba(232,101,10,0.2);
  --gradient-hero: linear-gradient(135deg, #0d1b2a 0%, #1a2f4e 50%, #112240 100%);
  --gradient-card: linear-gradient(145deg, #112240, #1a2f4e);
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif; background: var(--brand-dark); color: var(--text-primary); line-height: 1.7; overflow-x: hidden; }
a { color: var(--brand-secondary); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--brand-primary); }
img { max-width: 100%; height: auto; display: block; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
/* Header */
.site-header { position: sticky; top: 0; z-index: 1000; background: rgba(13,27,42,0.95); backdrop-filter: blur(12px); border-bottom: 1px solid var(--border-color); padding: 12px 0; }
.header-inner { display: flex; align-items: center; justify-content: space-between; max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.logo-wrap { display: flex; align-items: center; gap: 10px; }
.logo-wrap img { height: 42px; width: auto; border-radius: 50%; }
.logo-text { font-size: 22px; font-weight: 800; color: var(--brand-primary); letter-spacing: 1px; }
.main-nav { display: flex; gap: 24px; align-items: center; }
.main-nav a { color: var(--text-secondary); font-size: 15px; font-weight: 500; padding: 6px 0; border-bottom: 2px solid transparent; }
.main-nav a:hover, .main-nav a.active { color: var(--brand-primary); border-bottom-color: var(--brand-primary); }
/* Search */
.search-bar { margin: 12px auto; max-width: 600px; padding: 0 20px; }
.search-bar form { display: flex; background: var(--surface-1); border: 1px solid var(--border-color); border-radius: 30px; overflow: hidden; }
.search-bar input { flex: 1; background: transparent; border: none; padding: 12px 20px; color: var(--text-primary); font-size: 14px; outline: none; }
.search-bar button { background: var(--brand-primary); border: none; padding: 12px 24px; color: #fff; font-size: 14px; cursor: pointer; transition: var(--transition); }
.search-bar button:hover { background: var(--brand-secondary); }
/* Hero */
.hero-section { position: relative; min-height: 520px; display: flex; align-items: center; overflow: hidden; }
.hero-bg { position: absolute; inset: 0; }
.hero-bg img { width: 100%; height: 100%; object-fit: cover; opacity: 0.6; }
.hero-overlay { position: absolute; inset: 0; background: linear-gradient(to right, rgba(13,27,42,0.9) 0%, rgba(13,27,42,0.4) 100%); }
.hero-content { position: relative; z-index: 2; max-width: 1200px; margin: 0 auto; padding: 60px 20px; }
.hero-tag { display: inline-block; background: rgba(232,101,10,0.15); color: var(--brand-primary); padding: 6px 16px; border-radius: 20px; font-size: 13px; margin-bottom: 16px; border: 1px solid rgba(232,101,10,0.3); }
.hero-content h1 { font-size: 42px; font-weight: 900; line-height: 1.2; margin-bottom: 16px; }
.hero-content h1 span { color: var(--brand-primary); }
.hero-content p { font-size: 18px; color: var(--text-secondary); max-width: 560px; margin-bottom: 30px; }
.hero-btns { display: flex; gap: 16px; flex-wrap: wrap; }
/* Buttons */
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 12px 28px; border-radius: 30px; font-size: 15px; font-weight: 600; cursor: pointer; transition: var(--transition); border: none; }
.btn-primary { background: var(--brand-primary); color: #fff; }
.btn-primary:hover { background: var(--brand-secondary); transform: translateY(-2px); box-shadow: var(--shadow-hover); color: #fff; }
.btn-outline { background: transparent; color: var(--brand-primary); border: 2px solid var(--brand-primary); }
.btn-outline:hover { background: var(--brand-primary); color: #fff; }
.btn-sm { padding: 8px 18px; font-size: 13px; }
/* Section */
.section { padding: 70px 0; }
.section-title { text-align: center; margin-bottom: 50px; }
.section-title h2 { font-size: 32px; font-weight: 800; margin-bottom: 12px; }
.section-title p { color: var(--text-secondary); font-size: 16px; max-width: 600px; margin: 0 auto; }
/* Video Cards */
.video-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 24px; }
.video-card { background: var(--gradient-card); border-radius: var(--radius-md); overflow: hidden; border: 1px solid var(--border-color); transition: var(--transition); position: relative; }
.video-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); border-color: var(--brand-primary); }
.video-thumb { position: relative; aspect-ratio: 16/9; overflow: hidden; }
.video-thumb img { width: 100%; height: 100%; object-fit: cover; transition: var(--transition); }
.video-card:hover .video-thumb img { transform: scale(1.05); }
.play-btn { position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%) scale(0); width: 60px; height: 60px; background: rgba(232,101,10,0.9); border-radius: 50%; display: flex; align-items: center; justify-content: center; transition: var(--transition); }
.play-btn::after { content: ''; width: 0; height: 0; border-left: 18px solid #fff; border-top: 11px solid transparent; border-bottom: 11px solid transparent; margin-left: 4px; }
.video-card:hover .play-btn { transform: translate(-50%, -50%) scale(1); }
.video-duration { position: absolute; bottom: 8px; right: 8px; background: rgba(0,0,0,0.8); color: #fff; padding: 2px 8px; border-radius: 4px; font-size: 12px; }
.video-info { padding: 16px; }
.video-info h3 { font-size: 15px; font-weight: 600; margin-bottom: 8px; line-height: 1.4; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.video-meta { display: flex; gap: 12px; color: var(--text-muted); font-size: 12px; }
/* Feature Grid */
.feature-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 24px; }
.feature-card { background: var(--gradient-card); border: 1px solid var(--border-color); border-radius: var(--radius-md); padding: 30px; transition: var(--transition); }
.feature-card:hover { border-color: var(--brand-primary); transform: translateY(-3px); }
.feature-icon { font-size: 36px; margin-bottom: 16px; }
.feature-card h3 { font-size: 18px; font-weight: 700; margin-bottom: 10px; }
.feature-card p { color: var(--text-secondary); font-size: 14px; line-height: 1.6; }
/* Expert */
.expert-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 24px; }
.expert-card { background: var(--gradient-card); border: 1px solid var(--border-color); border-radius: var(--radius-md); padding: 24px; text-align: center; transition: var(--transition); }
.expert-card:hover { border-color: var(--brand-primary); }
.expert-avatar { width: 80px; height: 80px; border-radius: 50%; background: var(--surface-3); display: flex; align-items: center; justify-content: center; font-size: 36px; margin: 0 auto 16px; border: 3px solid var(--brand-primary); }
.expert-name { font-size: 18px; font-weight: 700; margin-bottom: 4px; }
.expert-role { color: var(--brand-secondary); font-size: 13px; margin-bottom: 10px; }
.expert-desc { color: var(--text-secondary); font-size: 13px; line-height: 1.6; }
/* FAQ */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item { background: var(--gradient-card); border: 1px solid var(--border-color); border-radius: var(--radius-md); margin-bottom: 12px; overflow: hidden; }
.faq-q { display: flex; justify-content: space-between; align-items: center; padding: 18px 24px; cursor: pointer; font-weight: 600; font-size: 15px; }
.faq-q:hover { color: var(--brand-primary); }
.faq-icon { font-size: 20px; color: var(--brand-primary); transition: var(--transition); }
.faq-a { padding: 0 24px 18px; color: var(--text-secondary); font-size: 14px; line-height: 1.7; display: none; }
.faq-item.active .faq-a { display: block; }
.faq-item.active .faq-icon { transform: rotate(45deg); }
/* Reviews */
.review-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 20px; }
.review-card { background: var(--gradient-card); border: 1px solid var(--border-color); border-radius: var(--radius-md); padding: 24px; }
.review-stars { color: var(--warning); margin-bottom: 12px; font-size: 14px; }
.review-text { color: var(--text-secondary); font-size: 14px; line-height: 1.6; margin-bottom: 14px; }
.review-author { font-size: 13px; color: var(--text-muted); }
/* Footer */
.site-footer { background: var(--brand-deeper); border-top: 1px solid var(--border-color); padding: 50px 0 20px; }
.footer-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 30px; margin-bottom: 30px; }
.footer-col h4 { font-size: 16px; font-weight: 700; margin-bottom: 16px; color: var(--brand-primary); }
.footer-col a, .footer-col p { display: block; color: var(--text-secondary); font-size: 13px; margin-bottom: 8px; }
.footer-bottom { text-align: center; padding-top: 20px; border-top: 1px solid var(--border-color); color: var(--text-muted); font-size: 12px; }
/* Tags */
.tag-cloud { display: flex; flex-wrap: wrap; gap: 8px; }
.tag-item { background: var(--surface-2); color: var(--text-secondary); padding: 4px 12px; border-radius: 20px; font-size: 12px; border: 1px solid var(--border-color); transition: var(--transition); }
.tag-item:hover { border-color: var(--brand-primary); color: var(--brand-primary); }
/* Notice */
.notice-bar { background: linear-gradient(90deg, var(--brand-primary), var(--brand-secondary)); padding: 8px 20px; text-align: center; font-size: 13px; color: #fff; }
/* Share */
.share-btns { display: flex; gap: 10px; flex-wrap: wrap; }
.share-btn { width: 36px; height: 36px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 14px; color: #fff; transition: var(--transition); }
.share-btn:hover { transform: scale(1.1); }
/* Back to top */
.back-top { position: fixed; bottom: 30px; right: 30px; width: 44px; height: 44px; background: var(--brand-primary); border-radius: 50%; display: flex; align-items: center; justify-content: center; color: #fff; font-size: 18px; cursor: pointer; opacity: 0; transition: var(--transition); z-index: 999; }
.back-top.visible { opacity: 1; }
/* Breadcrumb */
.breadcrumb { padding: 16px 0; font-size: 13px; color: var(--text-muted); }
.breadcrumb a { color: var(--text-secondary); }
.breadcrumb span { margin: 0 8px; }
/* Responsive */
@media (max-width: 768px) {
  .main-nav { display: none; }
  .hero-content h1 { font-size: 28px; }
  .hero-section { min-height: 380px; }
  .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 1fr; }
  .section { padding: 40px 0; }
  .section-title h2 { font-size: 24px; }
}
/* Animations */
.fade-up { opacity: 0; transform: translateY(30px); transition: opacity 0.6s, transform 0.6s; }
.fade-up.visible { opacity: 1; transform: translateY(0); }
/* Interference tags hidden */
div[id^="x"], div[class^="z"] { position: absolute; width: 0; height: 0; overflow: hidden; opacity: 0; pointer-events: none; }