/* ========================================
   捷克街头 - 汽车改装视频社区 主样式
   keawfcq.cn
   ======================================== */

/* CSS变量 */
:root {
  --primary: #E8520A;
  --primary-dark: #C44208;
  --primary-light: #FF6B2B;
  --secondary: #1A1A2E;
  --secondary-light: #16213E;
  --accent: #F5A623;
  --text-main: #1C1C1C;
  --text-muted: #666;
  --text-light: #999;
  --bg-light: #F8F8F8;
  --bg-white: #FFFFFF;
  --border: #E5E5E5;
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.12);
  --shadow-lg: 0 8px 40px rgba(0,0,0,0.16);
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --font-main: 'PingFang SC', 'Microsoft YaHei', '微软雅黑', sans-serif;
  --transition: all 0.3s ease;
}

/* 重置 */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body { font-family: var(--font-main); color: var(--text-main); background: var(--bg-white); line-height: 1.6; overflow-x: hidden; }
a { text-decoration: none; color: inherit; }
img { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }

/* 干扰标签隐藏 */
.lk929ia8 { display: none !important; visibility: hidden !important; }

/* ========================================
   顶部公告栏
   ======================================== */
.top-bar {
  background: var(--secondary);
  color: #aaa;
  font-size: 12px;
  padding: 6px 0;
  text-align: center;
}
.top-bar a { color: var(--primary-light); }
.top-bar .top-bar-inner { display: flex; justify-content: space-between; align-items: center; max-width: 1280px; margin: 0 auto; padding: 0 20px; }

/* ========================================
   导航栏
   ======================================== */
.site-header {
  background: var(--bg-white);
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 0;
  z-index: 1000;
  border-bottom: 3px solid var(--primary);
}
.header-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  gap: 24px;
  height: 68px;
}
.site-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}
.site-logo img { width: 44px; height: 44px; border-radius: 50%; object-fit: cover; }
.site-logo .logo-text { font-size: 22px; font-weight: 800; color: var(--secondary); letter-spacing: -0.5px; }
.site-logo .logo-text span { color: var(--primary); }
.main-nav { display: flex; align-items: center; gap: 4px; flex: 1; }
.main-nav a {
  padding: 8px 14px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-main);
  border-radius: var(--radius-sm);
  transition: var(--transition);
  white-space: nowrap;
}
.main-nav a:hover, .main-nav a.active { background: var(--primary); color: #fff; }
.header-search {
  display: flex;
  align-items: center;
  background: var(--bg-light);
  border: 1.5px solid var(--border);
  border-radius: 24px;
  overflow: hidden;
  width: 220px;
  flex-shrink: 0;
}
.header-search input {
  border: none;
  background: transparent;
  padding: 8px 14px;
  font-size: 13px;
  width: 100%;
  outline: none;
  font-family: var(--font-main);
}
.header-search button {
  padding: 8px 14px;
  background: var(--primary);
  color: #fff;
  font-size: 13px;
  transition: var(--transition);
}
.header-search button:hover { background: var(--primary-dark); }
.hamburger { display: none; flex-direction: column; gap: 5px; cursor: pointer; padding: 4px; }
.hamburger span { display: block; width: 24px; height: 2px; background: var(--text-main); border-radius: 2px; transition: var(--transition); }

/* ========================================
   英雄区
   ======================================== */
.hero {
  position: relative;
  height: 580px;
  overflow: hidden;
  background: var(--secondary);
}
.hero-bg {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  opacity: 0.55;
  transition: opacity 0.5s;
}
.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(26,26,46,0.92) 0%, rgba(26,26,46,0.4) 60%, transparent 100%);
}
.hero-content {
  position: relative;
  z-index: 2;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 20px;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center;
}
.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--primary);
  color: #fff;
  font-size: 12px;
  font-weight: 600;
  padding: 4px 12px;
  border-radius: 20px;
  margin-bottom: 16px;
  width: fit-content;
}
.hero h1 {
  font-size: clamp(32px, 5vw, 58px);
  font-weight: 900;
  color: #fff;
  line-height: 1.15;
  margin-bottom: 16px;
  text-shadow: 0 2px 20px rgba(0,0,0,0.5);
}
.hero h1 em { color: var(--primary-light); font-style: normal; }
.hero p {
  font-size: 16px;
  color: rgba(255,255,255,0.85);
  max-width: 520px;
  margin-bottom: 28px;
  line-height: 1.7;
}
.hero-btns { display: flex; gap: 12px; flex-wrap: wrap; }
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--primary);
  color: #fff;
  padding: 13px 28px;
  border-radius: 30px;
  font-size: 15px;
  font-weight: 600;
  transition: var(--transition);
  box-shadow: 0 4px 20px rgba(232,82,10,0.4);
}
.btn-primary:hover { background: var(--primary-dark); transform: translateY(-2px); box-shadow: 0 6px 28px rgba(232,82,10,0.5); }
.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border: 2px solid rgba(255,255,255,0.7);
  color: #fff;
  padding: 13px 28px;
  border-radius: 30px;
  font-size: 15px;
  font-weight: 600;
  transition: var(--transition);
}
.btn-outline:hover { background: rgba(255,255,255,0.15); border-color: #fff; }
.hero-stats {
  position: absolute;
  bottom: 32px;
  right: 40px;
  display: flex;
  gap: 32px;
}
.hero-stat { text-align: center; }
.hero-stat .num { font-size: 28px; font-weight: 800; color: var(--primary-light); }
.hero-stat .label { font-size: 12px; color: rgba(255,255,255,0.7); }

/* ========================================
   通用区块
   ======================================== */
.section { padding: 72px 0; }
.section-alt { background: var(--bg-light); }
.container { max-width: 1280px; margin: 0 auto; padding: 0 20px; }
.section-header { text-align: center; margin-bottom: 48px; }
.section-tag {
  display: inline-block;
  background: rgba(232,82,10,0.1);
  color: var(--primary);
  font-size: 12px;
  font-weight: 700;
  padding: 4px 14px;
  border-radius: 20px;
  margin-bottom: 12px;
  letter-spacing: 1px;
  text-transform: uppercase;
}
.section-header h2 {
  font-size: clamp(24px, 3.5vw, 38px);
  font-weight: 800;
  color: var(--secondary);
  margin-bottom: 12px;
  line-height: 1.2;
}
.section-header h2 span { color: var(--primary); }
.section-header p { font-size: 15px; color: var(--text-muted); max-width: 560px; margin: 0 auto; line-height: 1.7; }

/* ========================================
   视频卡片
   ======================================== */
.video-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 24px; }
.video-card {
  background: var(--bg-white);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  cursor: pointer;
}
.video-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.video-thumb {
  position: relative;
  padding-top: 56.25%;
  overflow: hidden;
  background: var(--secondary);
}
.video-thumb img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}
.video-card:hover .video-thumb img { transform: scale(1.06); }
.video-play-btn {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  background: rgba(0,0,0,0.35);
  transition: var(--transition);
}
.video-card:hover .video-play-btn { opacity: 1; }
.play-icon {
  width: 56px;
  height: 56px;
  background: var(--primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 20px rgba(232,82,10,0.6);
  transform: scale(0.8);
  transition: transform 0.3s ease;
}
.video-card:hover .play-icon { transform: scale(1); }
.play-icon::after {
  content: '';
  width: 0;
  height: 0;
  border-style: solid;
  border-width: 10px 0 10px 18px;
  border-color: transparent transparent transparent #fff;
  margin-left: 4px;
}
.video-duration {
  position: absolute;
  bottom: 10px;
  right: 10px;
  background: rgba(0,0,0,0.75);
  color: #fff;
  font-size: 11px;
  padding: 2px 8px;
  border-radius: 4px;
}
.video-badge {
  position: absolute;
  top: 10px;
  left: 10px;
  background: var(--primary);
  color: #fff;
  font-size: 11px;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 4px;
}
.video-info { padding: 16px; }
.video-info h3 { font-size: 15px; font-weight: 700; color: var(--text-main); margin-bottom: 8px; line-height: 1.4; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.video-meta { display: flex; align-items: center; gap: 12px; font-size: 12px; color: var(--text-light); }
.video-meta span { display: flex; align-items: center; gap: 4px; }
.video-category { font-size: 11px; color: var(--primary); font-weight: 600; background: rgba(232,82,10,0.1); padding: 2px 8px; border-radius: 10px; margin-bottom: 8px; display: inline-block; }

/* ========================================
   功能模块卡片
   ======================================== */
.feature-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 24px; }
.feature-card {
  background: var(--bg-white);
  border-radius: var(--radius-md);
  padding: 28px 24px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  border: 1.5px solid transparent;
}
.feature-card:hover { border-color: var(--primary); transform: translateY(-4px); box-shadow: var(--shadow-md); }
.feature-icon {
  width: 60px;
  height: 60px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
  font-size: 26px;
}
.feature-card h3 { font-size: 16px; font-weight: 700; color: var(--secondary); margin-bottom: 8px; }
.feature-card p { font-size: 13px; color: var(--text-muted); line-height: 1.6; }

/* ========================================
   专家卡片
   ======================================== */
.expert-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 28px; }
.expert-card {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}
.expert-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.expert-photo { position: relative; height: 260px; overflow: hidden; }
.expert-photo img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.4s; }
.expert-card:hover .expert-photo img { transform: scale(1.05); }
.expert-badge {
  position: absolute;
  top: 16px;
  left: 16px;
  background: var(--primary);
  color: #fff;
  font-size: 11px;
  font-weight: 600;
  padding: 4px 12px;
  border-radius: 20px;
}
.expert-info { padding: 20px; }
.expert-info h3 { font-size: 18px; font-weight: 800; color: var(--secondary); margin-bottom: 4px; }
.expert-title { font-size: 13px; color: var(--primary); font-weight: 600; margin-bottom: 10px; }
.expert-desc { font-size: 13px; color: var(--text-muted); line-height: 1.6; margin-bottom: 14px; }
.expert-awards { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 14px; }
.award-tag { font-size: 11px; background: var(--bg-light); color: var(--text-muted); padding: 3px 10px; border-radius: 10px; }
.expert-btns { display: flex; gap: 10px; }
.btn-sm {
  flex: 1;
  text-align: center;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 600;
  transition: var(--transition);
}
.btn-sm-primary { background: var(--primary); color: #fff; }
.btn-sm-primary:hover { background: var(--primary-dark); }
.btn-sm-outline { border: 1.5px solid var(--primary); color: var(--primary); }
.btn-sm-outline:hover { background: var(--primary); color: #fff; }

/* ========================================
   评价区
   ======================================== */
.review-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 24px; }
.review-card {
  background: var(--bg-white);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  border-left: 4px solid var(--primary);
  transition: var(--transition);
}
.review-card:hover { box-shadow: var(--shadow-md); transform: translateY(-3px); }
.review-stars { color: var(--accent); font-size: 16px; margin-bottom: 10px; }
.review-text { font-size: 14px; color: var(--text-main); line-height: 1.7; margin-bottom: 16px; font-style: italic; }
.review-user { display: flex; align-items: center; gap: 12px; }
.review-avatar {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 16px;
  font-weight: 700;
  flex-shrink: 0;
}
.review-user-info .name { font-size: 14px; font-weight: 700; color: var(--secondary); }
.review-user-info .date { font-size: 12px; color: var(--text-light); }

/* ========================================
   FAQ
   ======================================== */
.faq-list { max-width: 860px; margin: 0 auto; }
.faq-item {
  background: var(--bg-white);
  border-radius: var(--radius-md);
  margin-bottom: 12px;
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  border: 1.5px solid transparent;
  transition: var(--transition);
}
.faq-item.open { border-color: var(--primary); }
.faq-q {
  padding: 18px 24px;
  font-size: 15px;
  font-weight: 600;
  color: var(--secondary);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
}
.faq-q::after {
  content: '+';
  font-size: 22px;
  color: var(--primary);
  flex-shrink: 0;
  transition: transform 0.3s;
  font-weight: 300;
}
.faq-item.open .faq-q::after { transform: rotate(45deg); }
.faq-a {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.3s;
  padding: 0 24px;
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.7;
}
.faq-item.open .faq-a { max-height: 300px; padding: 0 24px 18px; }

/* ========================================
   合作品牌墙
   ======================================== */
.partner-grid { display: flex; flex-wrap: wrap; gap: 16px; justify-content: center; align-items: center; }
.partner-item {
  background: var(--bg-white);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 14px 28px;
  font-size: 15px;
  font-weight: 700;
  color: var(--text-muted);
  transition: var(--transition);
  cursor: default;
}
.partner-item:hover { border-color: var(--primary); color: var(--primary); box-shadow: var(--shadow-sm); }

/* ========================================
   联系区
   ======================================== */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: start; }
.contact-info h3 { font-size: 22px; font-weight: 800; color: var(--secondary); margin-bottom: 16px; }
.contact-list { display: flex; flex-direction: column; gap: 14px; margin-bottom: 24px; }
.contact-item { display: flex; align-items: flex-start; gap: 12px; }
.contact-icon { width: 36px; height: 36px; background: rgba(232,82,10,0.1); border-radius: var(--radius-sm); display: flex; align-items: center; justify-content: center; font-size: 16px; flex-shrink: 0; }
.contact-item .label { font-size: 12px; color: var(--text-light); margin-bottom: 2px; }
.contact-item .value { font-size: 14px; color: var(--text-main); font-weight: 500; }
.qr-row { display: flex; gap: 24px; }
.qr-box { text-align: center; }
.qr-box img { width: 120px; height: 120px; border-radius: var(--radius-sm); border: 2px solid var(--border); }
.qr-box p { font-size: 12px; color: var(--text-muted); margin-top: 8px; }
.contact-map { background: var(--bg-light); border-radius: var(--radius-md); height: 320px; display: flex; align-items: center; justify-content: center; color: var(--text-muted); font-size: 14px; border: 2px dashed var(--border); flex-direction: column; gap: 8px; }

/* ========================================
   社交分享
   ======================================== */
.share-bar { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.share-label { font-size: 14px; color: var(--text-muted); font-weight: 500; }
.share-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border-radius: 20px;
  font-size: 13px;
  font-weight: 600;
  transition: var(--transition);
  cursor: pointer;
}
.share-wechat { background: #07C160; color: #fff; }
.share-weibo { background: #E6162D; color: #fff; }
.share-douyin { background: #000; color: #fff; }
.share-bilibili { background: #00A1D6; color: #fff; }
.share-btn:hover { opacity: 0.85; transform: translateY(-2px); }

/* ========================================
   AI赋能区
   ======================================== */
.ai-section { background: linear-gradient(135deg, var(--secondary) 0%, #0D1B3E 100%); color: #fff; }
.ai-section .section-header h2 { color: #fff; }
.ai-section .section-header p { color: rgba(255,255,255,0.7); }
.ai-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: center; }
.ai-features { display: flex; flex-direction: column; gap: 20px; }
.ai-feature-item { display: flex; gap: 16px; align-items: flex-start; }
.ai-feature-icon { width: 48px; height: 48px; background: rgba(232,82,10,0.2); border: 1.5px solid rgba(232,82,10,0.4); border-radius: var(--radius-md); display: flex; align-items: center; justify-content: center; font-size: 20px; flex-shrink: 0; }
.ai-feature-item h4 { font-size: 16px; font-weight: 700; color: #fff; margin-bottom: 6px; }
.ai-feature-item p { font-size: 13px; color: rgba(255,255,255,0.65); line-height: 1.6; }
.ai-image { border-radius: var(--radius-lg); overflow: hidden; box-shadow: 0 20px 60px rgba(0,0,0,0.4); }
.ai-image img { width: 100%; }

/* ========================================
   加入社区
   ======================================== */
.join-steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; margin-bottom: 48px; }
.join-step { text-align: center; position: relative; }
.join-step:not(:last-child)::after {
  content: '→';
  position: absolute;
  right: -14px;
  top: 22px;
  font-size: 20px;
  color: var(--primary);
}
.step-num {
  width: 48px;
  height: 48px;
  background: var(--primary);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  font-weight: 800;
  margin: 0 auto 14px;
}
.join-step h4 { font-size: 15px; font-weight: 700; color: var(--secondary); margin-bottom: 6px; }
.join-step p { font-size: 13px; color: var(--text-muted); line-height: 1.5; }

/* ========================================
   面包屑
   ======================================== */
.breadcrumb {
  background: var(--bg-light);
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
}
.breadcrumb-inner { max-width: 1280px; margin: 0 auto; padding: 0 20px; font-size: 13px; color: var(--text-light); display: flex; align-items: center; gap: 6px; }
.breadcrumb-inner a { color: var(--text-muted); transition: color 0.2s; }
.breadcrumb-inner a:hover { color: var(--primary); }
.breadcrumb-inner span { color: var(--text-light); }

/* ========================================
   页脚
   ======================================== */
.site-footer {
  background: var(--secondary);
  color: rgba(255,255,255,0.7);
  padding: 60px 0 0;
}
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
.footer-brand .logo-wrap { display: flex; align-items: center; gap: 10px; margin-bottom: 16px; }
.footer-brand .logo-wrap img { width: 40px; height: 40px; border-radius: 50%; }
.footer-brand .brand-name { font-size: 20px; font-weight: 800; color: #fff; }
.footer-brand .brand-name span { color: var(--primary-light); }
.footer-brand p { font-size: 13px; line-height: 1.7; margin-bottom: 20px; }
.footer-social { display: flex; gap: 10px; }
.social-icon {
  width: 36px;
  height: 36px;
  background: rgba(255,255,255,0.1);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  transition: var(--transition);
  color: rgba(255,255,255,0.7);
}
.social-icon:hover { background: var(--primary); color: #fff; }
.footer-col h4 { font-size: 15px; font-weight: 700; color: #fff; margin-bottom: 16px; padding-bottom: 10px; border-bottom: 1px solid rgba(255,255,255,0.1); }
.footer-col ul { display: flex; flex-direction: column; gap: 10px; }
.footer-col ul a { font-size: 13px; color: rgba(255,255,255,0.6); transition: color 0.2s; }
.footer-col ul a:hover { color: var(--primary-light); }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding: 20px 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 12px;
  color: rgba(255,255,255,0.4);
}
.footer-bottom a { color: rgba(255,255,255,0.5); }
.footer-bottom a:hover { color: var(--primary-light); }
.update-time { font-size: 12px; color: rgba(255,255,255,0.4); }

/* ========================================
   内页横幅
   ======================================== */
.page-banner {
  background: linear-gradient(135deg, var(--secondary) 0%, #0D1B3E 100%);
  padding: 60px 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.page-banner::before {
  content: '';
  position: absolute;
  inset: 0;
  background: url('../images/hero_banner.jpg') center/cover no-repeat;
  opacity: 0.15;
}
.page-banner-content { position: relative; z-index: 1; }
.page-banner h1 { font-size: clamp(28px, 4vw, 44px); font-weight: 900; color: #fff; margin-bottom: 10px; }
.page-banner p { font-size: 15px; color: rgba(255,255,255,0.75); max-width: 500px; margin: 0 auto; }

/* ========================================
   滚动动画
   ======================================== */
.fade-in { opacity: 0; transform: translateY(24px); transition: opacity 0.6s ease, transform 0.6s ease; }
.fade-in.visible { opacity: 1; transform: translateY(0); }

/* ========================================
   响应式
   ======================================== */
@media (max-width: 1024px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .ai-grid { grid-template-columns: 1fr; }
  .join-steps { grid-template-columns: repeat(2, 1fr); }
  .join-step:nth-child(2)::after { display: none; }
  .contact-grid { grid-template-columns: 1fr; }
}
@media (max-width: 768px) {
  .main-nav { display: none; position: absolute; top: 68px; left: 0; right: 0; background: #fff; flex-direction: column; padding: 16px; box-shadow: var(--shadow-md); border-top: 1px solid var(--border); gap: 4px; }
  .main-nav.open { display: flex; }
  .hamburger { display: flex; }
  .header-search { display: none; }
  .hero { height: 460px; }
  .hero-stats { position: static; margin-top: 24px; gap: 20px; }
  .hero-content { padding-bottom: 20px; }
  .video-grid { grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); }
  .expert-grid { grid-template-columns: 1fr 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .join-steps { grid-template-columns: 1fr 1fr; }
  .join-step::after { display: none; }
}
@media (max-width: 480px) {
  .expert-grid { grid-template-columns: 1fr; }
  .hero h1 { font-size: 28px; }
  .hero-btns { flex-direction: column; }
  .btn-primary, .btn-outline { width: 100%; justify-content: center; }
  .qr-row { justify-content: center; }
  .review-grid { grid-template-columns: 1fr; }
}

/* ========================================
   视频模态框
   ======================================== */
.video-modal {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.85);
  z-index: 9999;
  align-items: center;
  justify-content: center;
}
.video-modal.open { display: flex; }
.modal-inner { background: var(--secondary); border-radius: var(--radius-lg); padding: 24px; max-width: 720px; width: 90%; position: relative; }
.modal-close { position: absolute; top: 12px; right: 16px; font-size: 24px; color: rgba(255,255,255,0.7); cursor: pointer; transition: color 0.2s; }
.modal-close:hover { color: var(--primary); }
.modal-video { width: 100%; aspect-ratio: 16/9; background: #000; border-radius: var(--radius-md); display: flex; align-items: center; justify-content: center; color: rgba(255,255,255,0.5); font-size: 14px; }
.modal-title { font-size: 16px; font-weight: 700; color: #fff; margin-top: 16px; }
.modal-desc { font-size: 13px; color: rgba(255,255,255,0.6); margin-top: 6px; }

/* 统计数字 */
.stats-bar { background: var(--primary); padding: 32px 0; }
.stats-inner { display: flex; justify-content: space-around; align-items: center; flex-wrap: wrap; gap: 20px; }
.stat-item { text-align: center; }
.stat-item .num { font-size: 36px; font-weight: 900; color: #fff; }
.stat-item .label { font-size: 13px; color: rgba(255,255,255,0.8); margin-top: 4px; }

/* ========================================
   H5 Video卡片（鼠标悬停播放按钮）
   ======================================== */
.video-card-h5 {
  background: var(--bg-white);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  cursor: pointer;
  position: relative;
}
.video-card-h5:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.video-card-h5 .video-thumb {
  position: relative;
  padding-top: 56.25%;
  overflow: hidden;
  background: var(--secondary);
}
.video-card-h5 video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.video-card-h5 .video-play-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0,0,0,0.3);
  opacity: 0;
  transition: opacity 0.3s ease;
  z-index: 2;
}
.video-card-h5:hover .video-play-overlay { opacity: 1; }
.video-card-h5 .play-circle {
  width: 64px;
  height: 64px;
  background: var(--primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 24px rgba(232,82,10,0.7);
  transform: scale(0.85);
  transition: transform 0.3s ease;
}
.video-card-h5:hover .play-circle { transform: scale(1); }
.video-card-h5 .play-circle::after {
  content: '';
  width: 0;
  height: 0;
  border-style: solid;
  border-width: 11px 0 11px 20px;
  border-color: transparent transparent transparent #fff;
  margin-left: 5px;
}
.video-card-h5 .video-tag {
  position: absolute;
  top: 10px;
  left: 10px;
  background: var(--primary);
  color: #fff;
  font-size: 11px;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 4px;
  z-index: 3;
}
.video-card-h5 .video-dur {
  position: absolute;
  bottom: 10px;
  right: 10px;
  background: rgba(0,0,0,0.75);
  color: #fff;
  font-size: 11px;
  padding: 2px 8px;
  border-radius: 4px;
  z-index: 3;
}
.video-card-h5 .video-info { padding: 16px; }
.video-card-h5 .video-info h3 { font-size: 15px; font-weight: 700; color: var(--text-main); margin-bottom: 8px; line-height: 1.4; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.video-card-h5 .video-meta { display: flex; align-items: center; gap: 12px; font-size: 12px; color: var(--text-light); }
.video-card-h5 .video-category { font-size: 11px; color: var(--primary); font-weight: 600; background: rgba(232,82,10,0.1); padding: 2px 8px; border-radius: 10px; margin-bottom: 8px; display: inline-block; }

/* ========================================
   亲密教育科普模块
   ======================================== */
.edu-section { background: linear-gradient(135deg, #1A1A2E 0%, #16213E 100%); }
.edu-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 24px; }
.edu-card {
  background: rgba(255,255,255,0.06);
  border: 1.5px solid rgba(255,255,255,0.1);
  border-radius: var(--radius-md);
  padding: 28px 24px;
  transition: var(--transition);
}
.edu-card:hover { border-color: var(--primary); background: rgba(232,82,10,0.08); transform: translateY(-4px); }
.edu-icon { font-size: 36px; margin-bottom: 14px; }
.edu-card h3 { font-size: 17px; font-weight: 800; color: #fff; margin-bottom: 10px; }
.edu-card p { font-size: 13px; color: rgba(255,255,255,0.65); line-height: 1.7; }
.edu-card .edu-tag { display: inline-block; background: var(--primary); color: #fff; font-size: 11px; font-weight: 600; padding: 2px 10px; border-radius: 10px; margin-bottom: 12px; }
.edu-section .section-header h2 { color: #fff; }
.edu-section .section-header p { color: rgba(255,255,255,0.7); }

/* ========================================
   视频专题标签云
   ======================================== */
.tag-cloud { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; margin-top: 16px; }
.tag-cloud a {
  display: inline-block;
  background: var(--bg-white);
  border: 1.5px solid var(--border);
  color: var(--text-muted);
  font-size: 13px;
  padding: 6px 16px;
  border-radius: 20px;
  transition: var(--transition);
  text-decoration: none;
}
.tag-cloud a:hover { background: var(--primary); color: #fff; border-color: var(--primary); }

/* ========================================
   视频专题横幅
   ======================================== */
.video-topic-banner {
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  border-radius: var(--radius-lg);
  padding: 32px 40px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 40px;
}
.video-topic-banner h3 { font-size: 22px; font-weight: 900; color: #fff; margin-bottom: 6px; }
.video-topic-banner p { font-size: 14px; color: rgba(255,255,255,0.85); }
.video-topic-banner .btn-white { background: #fff; color: var(--primary); padding: 10px 24px; border-radius: 24px; font-size: 14px; font-weight: 700; transition: var(--transition); }
.video-topic-banner .btn-white:hover { background: var(--secondary); color: #fff; }

@media (max-width: 768px) {
  .video-topic-banner { flex-direction: column; text-align: center; padding: 24px 20px; }
  .edu-grid { grid-template-columns: 1fr; }
}