:root {
  --color-primary: #00A1D6;
  --color-secondary: #FB7299;
  --color-bg: #ffffff;
  --color-text: #333333;
  --color-text-light: #666666;
  --color-border: #e0e0e0;
  --spacing-xs: 8px;
  --spacing-sm: 16px;
  --spacing-md: 24px;
  --spacing-lg: 32px;
  --spacing-xl: 48px;
  --border-radius: 8px;
  --transition: all 0.3s ease;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
}

.ui-style-11 {
  --color-primary: #00A1D6;
  --color-secondary: #FB7299;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-sm);
}

.site-header {
  background: #ffffff;
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-sm) 0;
}

.logo a {
  font-size: 24px;
  font-weight: 700;
  color: var(--color-primary);
  text-decoration: none;
  letter-spacing: 1px;
}

.main-nav {
  display: flex;
  gap: var(--spacing-md);
  white-space: nowrap;
}

.main-nav a {
  color: var(--color-text);
  text-decoration: none;
  font-weight: 500;
  transition: var(--transition);
  padding: 8px 12px;
  border-radius: var(--border-radius);
}

.main-nav a:hover {
  color: var(--color-primary);
  background: rgba(0, 161, 214, 0.1);
}

.site-main {
  min-height: calc(100vh - 200px);
  padding: var(--spacing-lg) 0;
}

.hero-section {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
  color: white;
  padding: var(--spacing-xl) 0;
  margin-bottom: var(--spacing-lg);
  border-radius: var(--border-radius);
}

.hero-title {
  font-size: 32px;
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
  line-height: 1.4;
}

.hero-subtitle {
  font-size: 18px;
  opacity: 0.95;
}

.intro-section {
  margin-bottom: var(--spacing-xl);
}

.intro-content p {
  font-size: 16px;
  line-height: 1.8;
  color: var(--color-text-light);
}

.video-list-section {
  margin-bottom: var(--spacing-xl);
}

.section-title {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: var(--spacing-md);
  color: var(--color-text);
  position: relative;
  padding-left: 16px;
}

.section-title::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 4px;
  height: 24px;
  background: var(--color-primary);
  border-radius: 2px;
}

.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--spacing-md);
}

.video-card {
  background: white;
  border-radius: var(--border-radius);
  overflow: hidden;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
  transition: var(--transition);
}

.video-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 16px rgba(0, 0, 0, 0.12);
}

.video-card__link {
  display: block;
  text-decoration: none;
  color: inherit;
}

.video-cover {
  position: relative;
  width: 100%;
  padding-top: 56.25%;
  background: #f5f5f5;
  overflow: hidden;
}

.video-cover img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.video-info {
  padding: var(--spacing-sm);
}

.video-title {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
  color: var(--color-text);
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

.video-meta {
  font-size: 14px;
  color: var(--color-text-light);
  margin-bottom: var(--spacing-xs);
}

.video-one-line {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.5;
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

.detail-page .video-player-section {
  margin-bottom: var(--spacing-lg);
}

.video-player {
  background: #000;
  border-radius: var(--border-radius);
  overflow: hidden;
}

.video-player-inner {
  position: relative;
  width: 100%;
  padding-top: 56.25%;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.player-play-btn {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  width: 80px;
  height: 80px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.9);
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 32px;
  color: var(--color-primary);
  transition: var(--transition);
}

.player-play-btn:hover {
  background: white;
  transform: translate(-50%, -50%) scale(1.1);
}

.detail-content {
  margin-bottom: var(--spacing-xl);
}

.detail-title {
  font-size: 36px;
  font-weight: 700;
  margin-bottom: var(--spacing-md);
  color: var(--color-text);
}

.detail-info-card {
  background: #f8f9fa;
  padding: var(--spacing-md);
  border-radius: var(--border-radius);
  margin-bottom: var(--spacing-lg);
}

.info-card-title {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
  color: var(--color-text);
}

.info-list {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--spacing-xs) var(--spacing-sm);
  font-size: 15px;
}

.info-list dt {
  font-weight: 600;
  color: var(--color-text);
}

.info-list dd {
  color: var(--color-text-light);
}

.detail-module {
  margin-bottom: var(--spacing-lg);
}

.module-title {
  font-size: 24px;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
  color: var(--color-text);
  padding-left: 12px;
  border-left: 4px solid var(--color-primary);
}

.module-content {
  font-size: 16px;
  line-height: 1.8;
  color: var(--color-text-light);
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: var(--spacing-sm);
}

.video-card--related {
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.06);
}

.page-header {
  text-align: center;
  margin-bottom: var(--spacing-xl);
  padding: var(--spacing-lg) 0;
  background: linear-gradient(135deg, rgba(0, 161, 214, 0.1) 0%, rgba(251, 114, 153, 0.1) 100%);
  border-radius: var(--border-radius);
}

.page-header h1 {
  font-size: 32px;
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
  color: var(--color-text);
}

.page-desc {
  font-size: 16px;
  color: var(--color-text-light);
}

.page--top .video-card {
  display: flex;
  flex-direction: row;
  padding: var(--spacing-sm);
}

.page--top .video-cover {
  width: 120px;
  padding-top: 0;
  height: 160px;
  flex-shrink: 0;
  margin-right: var(--spacing-sm);
}

.page--top .video-info {
  flex: 1;
  padding: 0;
}

.site-footer {
  background: #f8f9fa;
  padding: var(--spacing-lg) 0;
  text-align: center;
  color: var(--color-text-light);
  border-top: 1px solid var(--color-border);
}

.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 48px;
  height: 48px;
  background: var(--color-primary);
  color: white;
  border: none;
  border-radius: 50%;
  font-size: 20px;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: var(--transition);
  z-index: 99;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background: var(--color-secondary);
  transform: translateY(-4px);
}

@media (max-width: 768px) {
  .header-content {
    flex-direction: column;
    gap: var(--spacing-sm);
  }

  .main-nav {
    gap: var(--spacing-sm);
    font-size: 14px;
    overflow-x: auto;
    width: 100%;
    justify-content: space-between;
  }

  .main-nav a {
    padding: 6px 10px;
    font-size: 14px;
  }

  .hero-title {
    font-size: 24px;
  }

  .hero-subtitle {
    font-size: 16px;
  }

  .section-title {
    font-size: 22px;
  }

  .video-grid {
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: var(--spacing-sm);
  }

  .video-cover {
    padding-top: 45%;
  }

  .video-title {
    font-size: 16px;
  }

  .video-meta,
  .video-one-line {
    font-size: 13px;
  }

  .detail-title {
    font-size: 28px;
  }

  .page--top .video-card {
    flex-direction: column;
  }

  .page--top .video-cover {
    width: 100%;
    height: auto;
    padding-top: 56.25%;
    margin-right: 0;
    margin-bottom: var(--spacing-sm);
  }

  .page--top .video-info {
    padding: var(--spacing-sm);
  }
}