/* ========================================
   91 - 主样式文件
   Website: biqnwgb.cn
   ======================================== */

/* ---- CSS Reset & Base ---- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --primary:   #D4001A;   /* 品牌红 */
  --secondary: #0A0A0A;   /* 深黑 */
  --accent:    #FF6B00;   /* 活力橙 */
  --dark:      #111111;
  --dark2:     #1A1A1A;
  --dark3:     #222222;
  --light:     #F5F5F5;
  --white:     #FFFFFF;
  --gray:      #888888;
  --gray2:     #CCCCCC;
  --text:      #E0E0E0;
  --font-main: 'PingFang SC', 'Microsoft YaHei', '微软雅黑', sans-serif;
  --radius:    8px;
  --radius-lg: 16px;
  --shadow:    0 4px 24px rgba(0,0,0,0.4);
  --shadow-sm: 0 2px 10px rgba(0,0,0,0.3);
  --transition: 0.3s ease;
}

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: var(--font-main);
  background: var(--dark);
  color: var(--text);
  line-height: 1.7;
  overflow-x: hidden;
}

a { color: var(--primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--accent); }

img { max-width: 100%; height: auto; display: block; }

ul { list-style: none; }

.container { max-width: 1280px; margin: 0 auto; padding: 0 20px; }

.section { padding: 80px 0; }

.section-title {
  font-size: 2rem;
  font-weight: 800;
  color: var(--white);
  margin-bottom: 12px;
  letter-spacing: 0.02em;
}

.section-title span { color: var(--primary); }

.section-sub {
  font-size: 1rem;
  color: var(--gray);
  margin-bottom: 48px;
}

.btn {
  display: inline-block;
  padding: 12px 32px;
  border-radius: var(--radius);
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: all var(--transition);
  border: none;
  text-align: center;
}

.btn-primary {
  background: var(--primary);
  color: var(--white);
}
.btn-primary:hover { background: #b5001a; color: var(--white); transform: translateY(-2px); box-shadow: 0 6px 20px rgba(212,0,26,0.4); }

.btn-outline {
  background: transparent;
  border: 2px solid var(--primary);
  color: var(--primary);
}
.btn-outline:hover { background: var(--primary); color: var(--white); }

.btn-accent {
  background: var(--accent);
  color: var(--white);
}
.btn-accent:hover { background: #e05a00; color: var(--white); }

.tag {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 600;
  background: rgba(212,0,26,0.15);
  color: var(--primary);
  border: 1px solid rgba(212,0,26,0.3);
  margin: 2px;
}

/* ---- Header / Nav ---- */
#site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(10,10,10,0.96);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(212,0,26,0.2);
  box-shadow: 0 2px 20px rgba(0,0,0,0.5);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}

.logo-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.logo-icon {
  width: 48px;
  height: 48px;
  background: var(--primary);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  font-weight: 900;
  color: var(--white);
  letter-spacing: -1px;
  flex-shrink: 0;
}

.logo-text {
  display: flex;
  flex-direction: column;
}

.logo-name {
  font-size: 1.3rem;
  font-weight: 900;
  color: var(--white);
  line-height: 1.1;
  letter-spacing: 0.05em;
}

.logo-slogan {
  font-size: 0.65rem;
  color: var(--gray);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

#main-nav ul {
  display: flex;
  gap: 4px;
  align-items: center;
}

#main-nav ul li a {
  display: block;
  padding: 8px 14px;
  color: var(--gray2);
  font-size: 0.9rem;
  font-weight: 600;
  border-radius: var(--radius);
  transition: all var(--transition);
  white-space: nowrap;
}

#main-nav ul li a:hover,
#main-nav ul li a.active {
  color: var(--white);
  background: rgba(212,0,26,0.15);
}

.nav-cta {
  background: var(--primary) !important;
  color: var(--white) !important;
  border-radius: var(--radius) !important;
}
.nav-cta:hover { background: #b5001a !important; }

.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 8px;
}
.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--white);
  border-radius: 2px;
  transition: all var(--transition);
}

/* ---- Search Bar ---- */
.search-bar-wrap {
  background: var(--dark2);
  border-bottom: 1px solid rgba(255,255,255,0.06);
  padding: 10px 0;
}

.search-bar-inner {
  display: flex;
  align-items: center;
  gap: 10px;
  max-width: 700px;
  margin: 0 auto;
}

.search-input-wrap {
  flex: 1;
  position: relative;
}

.search-input-wrap input {
  width: 100%;
  padding: 10px 20px 10px 44px;
  background: var(--dark3);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 30px;
  color: var(--white);
  font-size: 0.9rem;
  font-family: var(--font-main);
  outline: none;
  transition: border-color var(--transition);
}
.search-input-wrap input:focus { border-color: var(--primary); }
.search-input-wrap input::placeholder { color: var(--gray); }

.search-icon {
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--gray);
  font-size: 1rem;
}

.search-btn {
  padding: 10px 24px;
  background: var(--primary);
  color: var(--white);
  border: none;
  border-radius: 30px;
  font-size: 0.9rem;
  font-weight: 700;
  cursor: pointer;
  font-family: var(--font-main);
  transition: background var(--transition);
}
.search-btn:hover { background: #b5001a; }

/* ---- Hero Banner ---- */
.hero-banner {
  position: relative;
  min-height: 90vh;
  display: flex;
  align-items: center;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  filter: brightness(0.45);
  transform: scale(1.05);
  transition: transform 8s ease;
}

.hero-banner:hover .hero-bg { transform: scale(1); }

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(10,10,10,0.85) 0%, rgba(212,0,26,0.15) 50%, rgba(10,10,10,0.7) 100%);
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 760px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(212,0,26,0.2);
  border: 1px solid rgba(212,0,26,0.4);
  border-radius: 30px;
  padding: 6px 16px;
  font-size: 0.8rem;
  color: var(--primary);
  font-weight: 600;
  margin-bottom: 24px;
  letter-spacing: 0.05em;
}

.hero-badge::before {
  content: '';
  display: block;
  width: 8px;
  height: 8px;
  background: var(--primary);
  border-radius: 50%;
  animation: pulse 1.5s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(1.3); }
}

.hero-title {
  font-size: clamp(2.2rem, 5vw, 3.8rem);
  font-weight: 900;
  color: var(--white);
  line-height: 1.15;
  margin-bottom: 20px;
  letter-spacing: -0.02em;
}

.hero-title .brand { color: var(--primary); }

.hero-desc {
  font-size: 1.1rem;
  color: rgba(255,255,255,0.75);
  margin-bottom: 36px;
  max-width: 560px;
  line-height: 1.8;
}

.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 48px; }

.hero-stats {
  display: flex;
  gap: 40px;
  flex-wrap: wrap;
}

.stat-item { text-align: center; }

.stat-num {
  font-size: 1.8rem;
  font-weight: 900;
  color: var(--primary);
  display: block;
  line-height: 1;
}

.stat-label {
  font-size: 0.8rem;
  color: var(--gray);
  margin-top: 4px;
}

.hero-scroll {
  position: absolute;
  bottom: 30px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--gray);
  font-size: 0.75rem;
  animation: bounce 2s infinite;
}

.hero-scroll::after {
  content: '';
  display: block;
  width: 1px;
  height: 40px;
  background: linear-gradient(to bottom, var(--gray), transparent);
}

@keyframes bounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(8px); }
}

/* ---- Video Cards ---- */
.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}

.video-card {
  background: var(--dark2);
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid rgba(255,255,255,0.06);
  transition: all var(--transition);
  cursor: pointer;
}

.video-card:hover {
  transform: translateY(-6px);
  border-color: rgba(212,0,26,0.3);
  box-shadow: 0 12px 40px rgba(212,0,26,0.15);
}

.video-thumb {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16/9;
}

.video-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.video-card:hover .video-thumb img { transform: scale(1.08); }

.play-btn {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0,0,0,0.3);
  opacity: 0;
  transition: opacity var(--transition);
}

.video-card:hover .play-btn { opacity: 1; }

.play-icon {
  width: 60px;
  height: 60px;
  background: var(--primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transform: scale(0.8);
  transition: transform var(--transition);
  box-shadow: 0 0 30px rgba(212,0,26,0.5);
}

.video-card:hover .play-icon { transform: scale(1); }

.play-icon::after {
  content: '';
  border-style: solid;
  border-width: 10px 0 10px 18px;
  border-color: transparent transparent transparent #fff;
  margin-left: 4px;
}

.video-duration {
  position: absolute;
  bottom: 8px;
  right: 8px;
  background: rgba(0,0,0,0.75);
  color: var(--white);
  font-size: 0.75rem;
  padding: 2px 8px;
  border-radius: 4px;
  font-weight: 600;
}

.video-info { padding: 16px; }

.video-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
}

.video-cat {
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--primary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.video-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 10px;
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.video-stats {
  display: flex;
  gap: 16px;
  font-size: 0.78rem;
  color: var(--gray);
}

.video-stats span { display: flex; align-items: center; gap: 4px; }

/* ---- Feature Cards ---- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 24px;
}

.feature-card {
  background: var(--dark2);
  border-radius: var(--radius-lg);
  padding: 32px 24px;
  border: 1px solid rgba(255,255,255,0.06);
  transition: all var(--transition);
  text-align: center;
}

.feature-card:hover {
  border-color: rgba(212,0,26,0.3);
  transform: translateY(-4px);
  box-shadow: var(--shadow);
}

.feature-icon {
  width: 64px;
  height: 64px;
  background: linear-gradient(135deg, rgba(212,0,26,0.2), rgba(255,107,0,0.1));
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  margin: 0 auto 20px;
  border: 1px solid rgba(212,0,26,0.2);
}

.feature-title {
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--white);
  margin-bottom: 10px;
}

.feature-desc {
  font-size: 0.88rem;
  color: var(--gray);
  line-height: 1.7;
}

/* ---- Expert Cards ---- */
.expert-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 28px;
}

.expert-card {
  background: var(--dark2);
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid rgba(255,255,255,0.06);
  transition: all var(--transition);
}

.expert-card:hover {
  border-color: rgba(212,0,26,0.3);
  transform: translateY(-4px);
  box-shadow: var(--shadow);
}

.expert-photo {
  position: relative;
  height: 220px;
  overflow: hidden;
}

.expert-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.expert-card:hover .expert-photo img { transform: scale(1.05); }

.expert-badge {
  position: absolute;
  top: 12px;
  left: 12px;
  background: var(--primary);
  color: var(--white);
  font-size: 0.72rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 4px;
}

.expert-info { padding: 20px; }

.expert-name {
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--white);
  margin-bottom: 4px;
}

.expert-role {
  font-size: 0.82rem;
  color: var(--primary);
  font-weight: 600;
  margin-bottom: 10px;
}

.expert-desc {
  font-size: 0.85rem;
  color: var(--gray);
  margin-bottom: 14px;
  line-height: 1.6;
}

.expert-actions { display: flex; gap: 8px; }

.expert-actions a {
  flex: 1;
  text-align: center;
  padding: 8px;
  border-radius: var(--radius);
  font-size: 0.8rem;
  font-weight: 700;
  transition: all var(--transition);
}

.btn-sm-primary {
  background: var(--primary);
  color: var(--white) !important;
}
.btn-sm-primary:hover { background: #b5001a; }

.btn-sm-outline {
  border: 1px solid rgba(255,255,255,0.15);
  color: var(--gray2) !important;
}
.btn-sm-outline:hover { border-color: var(--primary); color: var(--primary) !important; }

/* ---- Review Cards ---- */
.review-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}

.review-card {
  background: var(--dark2);
  border-radius: var(--radius-lg);
  padding: 28px;
  border: 1px solid rgba(255,255,255,0.06);
  transition: all var(--transition);
}

.review-card:hover {
  border-color: rgba(212,0,26,0.2);
  box-shadow: var(--shadow-sm);
}

.review-stars {
  color: #FFB800;
  font-size: 1rem;
  margin-bottom: 14px;
  letter-spacing: 2px;
}

.review-text {
  font-size: 0.9rem;
  color: var(--text);
  line-height: 1.8;
  margin-bottom: 18px;
  font-style: italic;
}

.review-text::before { content: '"'; color: var(--primary); font-size: 1.5rem; line-height: 0; vertical-align: -0.4em; margin-right: 4px; }
.review-text::after { content: '"'; color: var(--primary); font-size: 1.5rem; line-height: 0; vertical-align: -0.4em; margin-left: 4px; }

.reviewer {
  display: flex;
  align-items: center;
  gap: 12px;
}

.reviewer-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--white);
  flex-shrink: 0;
}

.reviewer-name {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--white);
}

.reviewer-info {
  font-size: 0.78rem;
  color: var(--gray);
}

/* ---- FAQ ---- */
.faq-list { max-width: 860px; margin: 0 auto; }

.faq-item {
  background: var(--dark2);
  border-radius: var(--radius);
  margin-bottom: 12px;
  border: 1px solid rgba(255,255,255,0.06);
  overflow: hidden;
}

.faq-question {
  padding: 20px 24px;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 1rem;
  font-weight: 700;
  color: var(--white);
  transition: background var(--transition);
  user-select: none;
}

.faq-question:hover { background: rgba(212,0,26,0.08); }

.faq-question.active { color: var(--primary); }

.faq-arrow {
  font-size: 0.8rem;
  color: var(--gray);
  transition: transform var(--transition);
  flex-shrink: 0;
}

.faq-question.active .faq-arrow { transform: rotate(180deg); color: var(--primary); }

.faq-answer {
  display: none;
  padding: 0 24px 20px;
  font-size: 0.9rem;
  color: var(--gray);
  line-height: 1.8;
  border-top: 1px solid rgba(255,255,255,0.06);
}

.faq-answer.open { display: block; }

/* ---- Partner Logos ---- */
.partner-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  justify-content: center;
  align-items: center;
}

.partner-logo {
  background: var(--dark2);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius);
  padding: 16px 28px;
  font-size: 1rem;
  font-weight: 800;
  color: var(--gray);
  transition: all var(--transition);
  letter-spacing: 0.05em;
  min-width: 120px;
  text-align: center;
}

.partner-logo:hover {
  border-color: var(--primary);
  color: var(--white);
  background: rgba(212,0,26,0.08);
}

/* ---- AI Section ---- */
.ai-section {
  background: linear-gradient(135deg, var(--dark2) 0%, rgba(212,0,26,0.05) 50%, var(--dark2) 100%);
  border-top: 1px solid rgba(212,0,26,0.15);
  border-bottom: 1px solid rgba(212,0,26,0.15);
}

.ai-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  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(212,0,26,0.15);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  flex-shrink: 0;
  border: 1px solid rgba(212,0,26,0.2);
}

.ai-feature-text h4 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 4px;
}

.ai-feature-text p {
  font-size: 0.85rem;
  color: var(--gray);
  line-height: 1.6;
}

.ai-image-wrap {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.ai-image-wrap img {
  width: 100%;
  border-radius: var(--radius-lg);
}

.ai-image-wrap::before {
  content: '';
  position: absolute;
  inset: -1px;
  border-radius: var(--radius-lg);
  border: 1px solid rgba(212,0,26,0.3);
  pointer-events: none;
  z-index: 1;
}

/* ---- Contact ---- */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: start;
}

.contact-info-list { display: flex; flex-direction: column; gap: 16px; }

.contact-item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  background: var(--dark2);
  border-radius: var(--radius);
  padding: 16px 20px;
  border: 1px solid rgba(255,255,255,0.06);
}

.contact-item-icon {
  font-size: 1.4rem;
  flex-shrink: 0;
  margin-top: 2px;
}

.contact-item-text strong {
  display: block;
  font-size: 0.85rem;
  color: var(--gray);
  margin-bottom: 2px;
}

.contact-item-text span {
  font-size: 0.95rem;
  color: var(--white);
  font-weight: 600;
}

.qr-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.qr-item {
  background: var(--dark2);
  border-radius: var(--radius);
  padding: 20px;
  text-align: center;
  border: 1px solid rgba(255,255,255,0.06);
}

.qr-code {
  width: 120px;
  height: 120px;
  background: var(--white);
  border-radius: 8px;
  margin: 0 auto 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.qr-code canvas { width: 100%; height: 100%; }

.qr-label {
  font-size: 0.85rem;
  color: var(--gray);
  font-weight: 600;
}

/* ---- Share Bar ---- */
.share-bar {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  align-items: center;
}

.share-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: 30px;
  font-size: 0.85rem;
  font-weight: 700;
  cursor: pointer;
  transition: all var(--transition);
  border: none;
  font-family: var(--font-main);
}

.share-wechat { background: #07C160; color: #fff; }
.share-wechat:hover { background: #05a050; }
.share-weibo { background: #E6162D; color: #fff; }
.share-weibo:hover { background: #c01020; }
.share-douyin { background: #000; color: #fff; border: 1px solid #333; }
.share-douyin:hover { background: #111; }
.share-bilibili { background: #00A1D6; color: #fff; }
.share-bilibili:hover { background: #0082b0; }

/* ---- Footer ---- */
#site-footer {
  background: var(--secondary);
  border-top: 1px solid rgba(255,255,255,0.06);
  padding: 60px 0 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  padding-bottom: 48px;
  border-bottom: 1px solid rgba(255,255,255,0.06);
}

.footer-brand .logo-wrap { margin-bottom: 16px; }

.footer-desc {
  font-size: 0.85rem;
  color: var(--gray);
  line-height: 1.8;
  margin-bottom: 20px;
}

.footer-social { display: flex; gap: 10px; }

.social-link {
  width: 36px;
  height: 36px;
  background: rgba(255,255,255,0.06);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
  color: var(--gray);
  transition: all var(--transition);
}

.social-link:hover { background: var(--primary); color: var(--white); }

.footer-col h4 {
  font-size: 0.9rem;
  font-weight: 800;
  color: var(--white);
  margin-bottom: 20px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.footer-col ul { display: flex; flex-direction: column; gap: 10px; }

.footer-col ul li a {
  font-size: 0.85rem;
  color: var(--gray);
  transition: color var(--transition);
}

.footer-col ul li a:hover { color: var(--primary); }

.footer-bottom {
  padding: 20px 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}

.footer-copy {
  font-size: 0.82rem;
  color: var(--gray);
}

.footer-links { display: flex; gap: 20px; }

.footer-links a {
  font-size: 0.82rem;
  color: var(--gray);
  transition: color var(--transition);
}

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

/* ---- Breadcrumb ---- */
.breadcrumb {
  padding: 14px 0;
  font-size: 0.82rem;
  color: var(--gray);
  border-bottom: 1px solid rgba(255,255,255,0.06);
  margin-bottom: 0;
}

.breadcrumb a { color: var(--gray); }
.breadcrumb a:hover { color: var(--primary); }
.breadcrumb span { margin: 0 6px; }

/* ---- Page Hero ---- */
.page-hero {
  background: linear-gradient(135deg, var(--dark2) 0%, rgba(212,0,26,0.08) 100%);
  padding: 60px 0;
  border-bottom: 1px solid rgba(255,255,255,0.06);
}

.page-hero h1 {
  font-size: 2.4rem;
  font-weight: 900;
  color: var(--white);
  margin-bottom: 12px;
}

.page-hero h1 span { color: var(--primary); }

.page-hero p {
  font-size: 1rem;
  color: var(--gray);
  max-width: 600px;
}

/* ---- Tabs ---- */
.tabs-nav {
  display: flex;
  gap: 4px;
  background: var(--dark2);
  border-radius: var(--radius);
  padding: 6px;
  margin-bottom: 32px;
  overflow-x: auto;
}

.tab-btn {
  padding: 10px 20px;
  border-radius: 6px;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--gray);
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
  background: transparent;
  border: none;
  font-family: var(--font-main);
}

.tab-btn.active, .tab-btn:hover {
  background: var(--primary);
  color: var(--white);
}

/* ---- Stats Bar ---- */
.stats-bar {
  background: var(--dark2);
  border-top: 1px solid rgba(212,0,26,0.2);
  border-bottom: 1px solid rgba(212,0,26,0.2);
  padding: 40px 0;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  text-align: center;
}

.stat-box { padding: 20px; }

.stat-box .num {
  font-size: 2.4rem;
  font-weight: 900;
  color: var(--primary);
  display: block;
  line-height: 1;
  margin-bottom: 8px;
}

.stat-box .label {
  font-size: 0.85rem;
  color: var(--gray);
}

/* ---- Scrollbar ---- */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--dark); }
::-webkit-scrollbar-thumb { background: var(--primary); border-radius: 3px; }

/* ---- Lazy load ---- */
img[data-src] { opacity: 0; transition: opacity 0.4s; }
img.loaded { opacity: 1; }

/* ---- Responsive ---- */
@media (max-width: 1024px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .ai-grid { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  .section { padding: 56px 0; }
  .section-title { font-size: 1.6rem; }

  #main-nav { display: none; position: absolute; top: 70px; left: 0; right: 0; background: rgba(10,10,10,0.98); padding: 16px; border-bottom: 1px solid rgba(212,0,26,0.2); }
  #main-nav.open { display: block; }
  #main-nav ul { flex-direction: column; gap: 4px; }
  #main-nav ul li a { padding: 12px 16px; }

  .hamburger { display: flex; }

  .hero-banner { min-height: 70vh; }
  .hero-stats { gap: 24px; }

  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr; gap: 32px; }
  .footer-bottom { flex-direction: column; text-align: center; }

  .video-grid { grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); }
  .expert-grid { grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); }
  .review-grid { grid-template-columns: 1fr; }
  .qr-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 480px) {
  .hero-actions { flex-direction: column; }
  .hero-actions .btn { text-align: center; }
  .stats-grid { grid-template-columns: 1fr 1fr; }
  .partner-grid { gap: 12px; }
  .share-bar { justify-content: center; }
}

/* ---- 补充缺失样式 ---- */
.ai-content { flex: 1; }
.ai-image { flex: 1; }
.tabs-wrap { margin-top: 0; }
.tab-content { animation: fadeIn 0.3s ease; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }

/* 视频弹窗 */
#video-modal { animation: fadeIn 0.2s ease; }
#video-modal video { width: 100%; border-radius: 8px; background: #000; }

/* 触摸设备：始终显示播放按钮 */
@media (hover: none) {
  .play-btn { opacity: 1; background: rgba(0,0,0,0.2); }
  .play-icon { transform: scale(0.9); }
}

/* 分享按钮 */
.share-bar { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; }
.share-btn { padding: 10px 20px; border: none; border-radius: 8px; font-size: 0.85rem; font-weight: 700; cursor: pointer; color: #fff; transition: all 0.2s; font-family: var(--font-main); }
.share-wechat { background: #07C160; }
.share-weibo { background: #E6162D; }
.share-douyin { background: #161823; border: 1px solid #FE2C55; }
.share-bilibili { background: #00A1D6; }
.share-wechat:hover { background: #05a050; }
.share-weibo:hover { background: #c01020; }
.share-douyin:hover { background: #111; }
.share-bilibili:hover { background: #0082b0; }

/* 移动端视频卡片优化 */
@media (max-width: 600px) {
  .video-grid { grid-template-columns: 1fr; }
  .play-icon { width: 48px; height: 48px; }
  .play-icon::after { border-width: 8px 0 8px 14px; }
  .expert-grid { grid-template-columns: 1fr; }
  .ai-grid { grid-template-columns: 1fr; gap: 32px; }
  .page-hero h1 { font-size: 1.5rem; }
  .ai-image { order: -1; }
}