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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  line-height: 1.6;
  color: #333;
  background: #f5f5f5;
}

.ui-style-5 {
  --primary-color: #1a73e8;
  --text-color: #333;
  --bg-color: #f5f5f5;
  --card-bg: #fff;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.site-header {
  background: var(--card-bg);
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 60px;
}

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

.main-nav {
  display: flex;
  gap: 8px;
}

.main-nav a {
  padding: 8px 16px;
  text-decoration: none;
  color: var(--text-color);
  border-radius: 4px;
  transition: background 0.2s;
  white-space: nowrap;
}

.main-nav a:hover,
.main-nav a.active {
  background: var(--primary-color);
  color: white;
}

.main-content {
  min-height: calc(100vh - 140px);
  padding: 40px 0;
}

.hero-section {
  background: linear-gradient(135deg, var(--primary-color) 0%, #667eea 100%);
  color: white;
  padding: 60px 20px;
  text-align: center;
  margin-bottom: 40px;
}

.hero-title {
  font-size: 32px;
  line-height: 1.4;
  font-weight: 600;
}

.site-intro {
  background: var(--card-bg);
  padding: 30px 0;
  margin-bottom: 40px;
}

.site-intro p {
  font-size: 16px;
  line-height: 1.8;
  color: #555;
}

.video-section {
  margin-bottom: 60px;
}

.section-header {
  margin-bottom: 20px;
}

.section-header h2 {
  font-size: 28px;
  color: var(--text-color);
  padding-bottom: 10px;
  border-bottom: 3px solid var(--primary-color);
  display: inline-block;
}

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

.video-card {
  background: var(--card-bg);
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  transition: transform 0.2s, box-shadow 0.2s;
}

.video-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 4px 16px rgba(0,0,0,0.15);
}

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

.video-cover {
  position: relative;
  padding-top: 56.25%;
  overflow: hidden;
  background: #e0e0e0;
}

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

.video-info {
  padding: 16px;
}

.video-title {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

.video-one-line {
  font-size: 14px;
  color: #666;
  margin-bottom: 8px;
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

.video-meta {
  display: flex;
  gap: 12px;
  font-size: 13px;
  color: #999;
}

.page-header {
  background: var(--card-bg);
  padding: 30px;
  border-radius: 8px;
  margin-bottom: 30px;
}

.page-header h1 {
  font-size: 32px;
  margin-bottom: 10px;
}

.page-desc {
  font-size: 16px;
  color: #666;
}

.top-list__items {
  list-style: none;
  background: var(--card-bg);
  border-radius: 8px;
  overflow: hidden;
}

.top-item {
  border-bottom: 1px solid #eee;
  transition: background 0.2s;
}

.top-item:hover {
  background: #f9f9f9;
}

.top-item__link {
  display: flex;
  align-items: center;
  gap: 20px;
  padding: 20px;
  text-decoration: none;
  color: inherit;
}

.top-rank {
  font-size: 24px;
  font-weight: bold;
  color: var(--primary-color);
  min-width: 40px;
  text-align: center;
}

.top-item .video-cover {
  width: 120px;
  height: 68px;
  flex-shrink: 0;
  padding-top: 0;
}

.top-item .video-cover img {
  position: relative;
}

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

.group {
  margin-bottom: 40px;
}

.group__title {
  font-size: 24px;
  margin-bottom: 20px;
  color: var(--primary-color);
}

.group__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}

.layout__container {
  display: grid;
  grid-template-columns: 250px 1fr;
  gap: 30px;
}

.layout__side--filters {
  background: var(--card-bg);
  padding: 20px;
  border-radius: 8px;
  height: fit-content;
}

.filter-section h3 {
  margin-bottom: 10px;
}

.detail-page {
  background: var(--card-bg);
  border-radius: 8px;
  padding: 30px;
}

.video-player-section {
  margin-bottom: 30px;
}

.video-player {
  max-width: 1000px;
  margin: 0 auto;
}

.video-player-inner {
  position: relative;
  width: 100%;
  padding-top: 56.25%;
  background: #000;
  border-radius: 8px;
  overflow: hidden;
}

.player-play-btn {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  width: 80px;
  height: 80px;
  border: none;
  border-radius: 50%;
  background: rgba(255,255,255,0.9);
  cursor: pointer;
  transition: transform 0.2s;
}

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

.player-play-icon {
  font-size: 32px;
  color: var(--primary-color);
}

.detail-header h1 {
  font-size: 36px;
  margin-bottom: 20px;
}

.detail-module {
  margin-bottom: 30px;
  padding-bottom: 30px;
  border-bottom: 1px solid #eee;
}

.detail-module h2 {
  font-size: 24px;
  margin-bottom: 15px;
  color: var(--primary-color);
}

.detail-module p {
  font-size: 16px;
  line-height: 1.8;
  color: #555;
}

.info-list {
  display: grid;
  grid-template-columns: 100px 1fr;
  gap: 12px 20px;
  font-size: 16px;
}

.info-list dt {
  font-weight: 600;
  color: #666;
}

.info-list dd {
  color: #333;
}

.tags-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.tag {
  background: #e3f2fd;
  color: var(--primary-color);
  padding: 6px 12px;
  border-radius: 4px;
  font-size: 14px;
}

.related-section {
  border-bottom: none;
}

.site-footer {
  background: var(--card-bg);
  padding: 30px 0;
  text-align: center;
  color: #666;
  border-top: 1px solid #eee;
}

.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 50px;
  height: 50px;
  background: var(--primary-color);
  color: white;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  font-size: 24px;
  display: none;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 8px rgba(0,0,0,0.2);
  transition: transform 0.2s;
}

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

.back-to-top.show {
  display: flex;
}

@media (max-width: 768px) {
  .header-container {
    flex-direction: column;
    height: auto;
    padding: 10px;
  }

  .main-nav {
    flex-wrap: nowrap;
    overflow-x: auto;
    width: 100%;
    padding: 10px 0;
  }

  .main-nav a {
    padding: 6px 12px;
    font-size: 14px;
  }

  .video-grid {
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: 16px;
  }

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

  .layout__container {
    grid-template-columns: 1fr;
  }

  .top-item__link {
    flex-direction: column;
    align-items: flex-start;
  }

  .top-item .video-cover {
    width: 100%;
    height: auto;
    padding-top: 56.25%;
  }

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

  .detail-header h1 {
    font-size: 24px;
  }
}