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

:root {
  --primary-color: #1a1a1a;
  --secondary-color: #f5f5f5;
  --accent-color: #ff6b6b;
  --text-color: #333;
  --text-light: #666;
  --border-color: #e0e0e0;
  --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  --transition: all 0.3s ease;
}

body.ui-style-0 {
  --primary-color: #000;
  --secondary-color: #fff;
  --accent-color: #00d4ff;
  --text-color: #fff;
  --text-light: #ccc;
  background: #000;
  color: #fff;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  line-height: 1.6;
  color: var(--text-color);
  background: var(--secondary-color);
}

.site-header {
  background: var(--primary-color);
  color: #fff;
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow);
}

.header-container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-logo a {
  font-size: 1.5rem;
  font-weight: 700;
  color: #fff;
  text-decoration: none;
}

.site-nav {
  display: flex;
  gap: 1.5rem;
  white-space: nowrap;
  overflow-x: auto;
  overflow-y: hidden;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

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

.site-nav a {
  color: #fff;
  text-decoration: none;
  padding: 0.5rem 1rem;
  border-radius: 4px;
  transition: var(--transition);
  white-space: nowrap;
}

.site-nav a:hover,
.site-nav a.active {
  background: var(--accent-color);
}

.main-content {
  min-height: 70vh;
}

.hero-section {
  background: linear-gradient(135deg, var(--primary-color) 0%, #333 100%);
  color: #fff;
  padding: 4rem 0;
  text-align: center;
}

.hero-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
}

.hero-title {
  font-size: 2rem;
  margin-bottom: 1rem;
  font-weight: 700;
}

.hero-desc {
  font-size: 1.1rem;
  opacity: 0.9;
  max-width: 800px;
  margin: 0 auto;
}

.intro-section {
  padding: 2rem 0;
  background: #fff;
}

.ui-style-0 .intro-section {
  background: #111;
}

.section-container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 1rem;
}

.video-section {
  padding: 3rem 0;
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
}

.section-title {
  font-size: 1.5rem;
  font-weight: 600;
}

.section-more {
  color: var(--accent-color);
  text-decoration: none;
  transition: var(--transition);
}

.section-more:hover {
  opacity: 0.8;
}

.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
}

.video-card {
  background: #fff;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: var(--transition);
}

.ui-style-0 .video-card {
  background: #1a1a1a;
}

.video-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

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

.video-cover {
  position: relative;
  padding-top: 56.25%;
  overflow: hidden;
  background: #f0f0f0;
}

.ui-style-0 .video-cover {
  background: #2a2a2a;
}

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

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

.video-info {
  padding: 1rem;
}

.video-title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

.video-one-line {
  font-size: 0.9rem;
  color: var(--text-light);
  margin-bottom: 0.5rem;
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

.video-meta {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.meta-item {
  font-size: 0.85rem;
  color: var(--text-light);
  background: var(--secondary-color);
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
}

.ui-style-0 .meta-item {
  background: #2a2a2a;
}

.page-header {
  background: linear-gradient(135deg, var(--primary-color) 0%, #333 100%);
  color: #fff;
  padding: 3rem 0;
  text-align: center;
}

.page-title {
  font-size: 2rem;
  margin-bottom: 0.5rem;
}

.page-desc {
  font-size: 1.1rem;
  opacity: 0.9;
}

.video-player-section {
  padding: 2rem 0;
  background: #000;
}

.video-player {
  max-width: 1200px;
  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-radius: 50%;
  background: rgba(255, 255, 255, 0.9);
  border: none;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
}

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

.player-play-icon {
  font-size: 2rem;
  color: #000;
}

.detail-title-section {
  padding: 2rem 0;
}

.detail-title {
  font-size: 2rem;
  font-weight: 700;
}

.detail-info-section {
  padding: 2rem 0;
  background: #fff;
}

.ui-style-0 .detail-info-section {
  background: #111;
}

.info-grid {
  display: grid;
  gap: 1rem;
  margin-top: 1rem;
}

.info-item {
  display: flex;
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--border-color);
}

.info-label {
  font-weight: 600;
  min-width: 100px;
}

.info-value {
  flex: 1;
  color: var(--text-light);
}

.detail-module {
  padding: 2rem 0;
}

.module-title {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

.module-content {
  line-height: 1.8;
}

.tag-list {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.tag-item {
  background: var(--accent-color);
  color: #fff;
  padding: 0.5rem 1rem;
  border-radius: 20px;
  font-size: 0.9rem;
}

.related-section {
  padding: 3rem 0;
}

.site-footer {
  background: var(--primary-color);
  color: #fff;
  padding: 2rem 0;
  text-align: center;
  margin-top: 3rem;
}

.footer-container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 1rem;
}

.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background: var(--accent-color);
  color: #fff;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  display: none;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow);
  transition: var(--transition);
  z-index: 99;
}

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

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

@media (max-width: 768px) {
  .header-container {
    flex-direction: column;
    gap: 1rem;
  }

  .site-nav {
    width: 100%;
    justify-content: flex-start;
    gap: 0.5rem;
    padding-bottom: 0.5rem;
  }

  .site-nav a {
    padding: 0.4rem 0.8rem;
    font-size: 0.9rem;
  }

  .hero-title {
    font-size: 1.5rem;
  }

  .hero-desc {
    font-size: 1rem;
  }

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

  .video-info {
    padding: 0.75rem;
  }

  .video-title {
    font-size: 0.9rem;
  }

  .video-one-line {
    font-size: 0.85rem;
  }

  .detail-title {
    font-size: 1.5rem;
  }

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

  .player-play-icon {
    font-size: 1.5rem;
  }

  .back-to-top {
    bottom: 1rem;
    right: 1rem;
    width: 40px;
    height: 40px;
    font-size: 1.2rem;
  }
}

@media (max-width: 480px) {
  .video-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .video-cover {
    padding-top: 65%;
  }
}