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

:root {
  --primary-color: #ff6700;
  --bg-color: #ffffff;
  --text-color: #333333;
  --text-secondary: #666666;
  --border-color: #e5e5e5;
  --hover-bg: #fff5f0;
  --card-shadow: 0 2px 8px rgba(0,0,0,0.08);
  --card-hover-shadow: 0 4px 16px rgba(255,103,0,0.2);
}

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

body.ui-style-4 {
  --primary-color: #ff6700;
}

a {
  text-decoration: none;
  color: inherit;
}

.site-header {
  background: #fff;
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}

.site-nav {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  gap: 30px;
  height: 60px;
  white-space: nowrap;
  overflow-x: auto;
  overflow-y: hidden;
}

.site-nav::-webkit-scrollbar {
  display: none;
}

.site-nav a {
  color: var(--text-color);
  transition: color 0.3s;
  flex-shrink: 0;
}

.site-nav a:hover {
  color: var(--primary-color);
}

.site-logo {
  font-size: 24px;
  font-weight: bold;
  color: var(--primary-color) !important;
  margin-right: auto;
}

.home-main,
.list-main,
.detail-main {
  max-width: 1400px;
  margin: 0 auto;
  padding: 40px 20px;
}

.hero-section {
  text-align: center;
  padding: 60px 20px;
  background: linear-gradient(135deg, #ff6700 0%, #ff8f3f 100%);
  color: white;
  border-radius: 16px;
  margin-bottom: 40px;
}

.hero-title {
  font-size: 32px;
  margin-bottom: 20px;
  font-weight: 600;
}

.hero-desc {
  font-size: 16px;
  line-height: 1.8;
  max-width: 800px;
  margin: 0 auto;
  opacity: 0.95;
}

.intro-section {
  background: #fff;
  padding: 30px;
  border-radius: 12px;
  margin-bottom: 40px;
  box-shadow: var(--card-shadow);
  line-height: 1.8;
}

.video-section {
  margin-bottom: 50px;
}

.section-title {
  font-size: 28px;
  margin-bottom: 25px;
  padding-left: 15px;
  border-left: 4px solid var(--primary-color);
}

.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 25px;
}

.video-card {
  background: #fff;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--card-shadow);
  transition: all 0.3s ease;
}

.video-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--card-hover-shadow);
}

.video-card__link {
  display: block;
}

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

.video-cover img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s;
}

.video-card:hover .video-cover img {
  transform: scale(1.05);
}

.video-info {
  padding: 15px;
}

.video-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  line-height: 1.4;
}

.video-one-line {
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 10px;
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

.video-meta {
  display: flex;
  gap: 10px;
  font-size: 12px;
  color: var(--text-secondary);
}

.video-meta span {
  padding: 2px 8px;
  background: var(--hover-bg);
  border-radius: 4px;
}

.page-header {
  text-align: center;
  margin-bottom: 40px;
}

.page-header h1 {
  font-size: 36px;
  margin-bottom: 15px;
}

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

.page--top .top-list__items {
  list-style: none;
}

.top-list__item {
  display: flex;
  align-items: center;
  gap: 20px;
  background: #fff;
  padding: 20px;
  margin-bottom: 15px;
  border-radius: 12px;
  box-shadow: var(--card-shadow);
  transition: all 0.3s;
}

.top-list__item:hover {
  box-shadow: var(--card-hover-shadow);
  transform: translateX(5px);
}

.top-rank {
  font-size: 32px;
  font-weight: bold;
  color: var(--primary-color);
  min-width: 50px;
  text-align: center;
}

.top-cover {
  width: 120px;
  height: 68px;
  flex-shrink: 0;
  border-radius: 8px;
  overflow: hidden;
}

.top-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.top-info {
  flex: 1;
}

.top-info h3 {
  font-size: 18px;
  margin-bottom: 8px;
}

.top-info h3 a:hover {
  color: var(--primary-color);
}

.video-player-section {
  margin-bottom: 40px;
}

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

.video-player-inner {
  position: relative;
  width: 100%;
  padding-top: 56.25%;
  background: #000;
  border-radius: 12px;
  overflow: hidden;
}

.player-play-btn {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  width: 80px;
  height: 80px;
  border: none;
  background: rgba(255, 103, 0, 0.9);
  border-radius: 50%;
  cursor: pointer;
  transition: all 0.3s;
}

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

.player-play-icon {
  font-size: 32px;
  color: white;
  display: block;
  padding-left: 4px;
}

.detail-header {
  text-align: center;
  margin-bottom: 30px;
}

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

.detail-info,
.detail-module {
  background: #fff;
  padding: 30px;
  border-radius: 12px;
  margin-bottom: 25px;
  box-shadow: var(--card-shadow);
}

.detail-info h2,
.detail-module h2 {
  font-size: 22px;
  margin-bottom: 20px;
  color: var(--primary-color);
}

.info-list {
  display: grid;
  gap: 12px;
  line-height: 1.8;
}

.info-list dt {
  display: inline-block;
  font-weight: 600;
  min-width: 80px;
}

.info-list dd {
  display: inline;
}

.detail-module p {
  line-height: 1.8;
  text-align: justify;
}

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

.tag {
  padding: 6px 15px;
  background: var(--hover-bg);
  color: var(--primary-color);
  border-radius: 20px;
  font-size: 14px;
}

.related-section {
  margin-top: 50px;
}

.related-section h2 {
  font-size: 28px;
  margin-bottom: 25px;
  padding-left: 15px;
  border-left: 4px solid var(--primary-color);
}

.site-footer {
  background: #f8f8f8;
  padding: 30px 20px;
  text-align: center;
  color: var(--text-secondary);
  border-top: 1px solid var(--border-color);
}

.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;
  display: none;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  box-shadow: 0 4px 12px rgba(255, 103, 0, 0.3);
  transition: all 0.3s;
  z-index: 99;
}

.back-to-top:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 16px rgba(255, 103, 0, 0.4);
}

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

@media (max-width: 768px) {
  .site-nav {
    gap: 15px;
    padding: 0 15px;
  }

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

  .hero-desc {
    font-size: 14px;
  }

  .section-title,
  .related-section h2 {
    font-size: 22px;
  }

  .video-grid {
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: 15px;
  }

  .video-cover {
    padding-top: 56.25%;
  }

  .video-info {
    padding: 12px;
  }

  .video-title {
    font-size: 14px;
  }

  .top-list__item {
    flex-wrap: wrap;
    gap: 15px;
  }

  .top-rank {
    font-size: 24px;
    min-width: 40px;
  }

  .top-cover {
    width: 100px;
    height: 56px;
  }

  .detail-header h1 {
    font-size: 26px;
  }

  .detail-info,
  .detail-module {
    padding: 20px 15px;
  }

  .player-play-btn {
    width: 60px;
    height: 60px;
  }

  .player-play-icon {
    font-size: 24px;
  }
}

@media (max-width: 480px) {
  .site-nav {
    gap: 12px;
  }

  .site-logo {
    font-size: 20px;
  }

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

  .video-cover {
    padding-top: 56.25%;
  }
}