:root {
  --primary-color: #0099FF;
  --secondary-color: #FF6B35;
  --bg-color: #FFFFFF;
  --text-color: #1A1A1A;
  --border-color: #E0E0E0;
  --hover-color: #F5F5F5;
  --shadow: 0 2px 8px rgba(0,0,0,0.1);
  --radius: 8px;
}

* {
  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: var(--text-color);
  background: var(--bg-color);
}

.ui-style-2 body {
  background: #FAFAFA;
}

a {
  color: var(--primary-color);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--secondary-color);
}

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

.site-header {
  background: var(--bg-color);
  border-bottom: 1px solid var(--border-color);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow);
}

.site-header .container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: nowrap;
}

.site-logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-color);
  white-space: nowrap;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  flex-wrap: nowrap;
}

.site-nav a {
  font-size: 1rem;
  font-weight: 500;
  white-space: nowrap;
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius);
  transition: background 0.2s ease;
}

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

.site-main {
  max-width: 1200px;
  margin: 2rem auto;
  padding: 0 1rem;
}

.section-hot,
.section-top,
.section-latest,
.page-header,
.video-list-section,
.video-detail-section,
.video-info-section,
.video-content-section,
.video-related-section {
  margin-bottom: 3rem;
}

.section-title {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  color: var(--text-color);
  border-left: 4px solid var(--primary-color);
  padding-left: 1rem;
}

.page-header {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  padding: 2rem;
  border-radius: var(--radius);
  color: white;
  margin-bottom: 2rem;
}

.page-header h1 {
  font-size: 2rem;
  margin-bottom: 1rem;
}

.page-intro {
  font-size: 1rem;
  line-height: 1.8;
  opacity: 0.95;
}

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

.video-card {
  background: white;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  display: flex;
  flex-direction: column;
}

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

.video-cover {
  position: relative;
  width: 100%;
  padding-top: 150%;
  background: #F0F0F0;
  overflow: hidden;
}

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

.video-info {
  padding: 1rem;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.video-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-color);
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.video-meta {
  font-size: 0.875rem;
  color: #666;
  margin-bottom: 0.5rem;
}

.video-one-line {
  font-size: 0.875rem;
  color: #666;
  line-height: 1.5;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-top: auto;
}

.video-player-section {
  margin-bottom: 2rem;
}

.video-player {
  position: relative;
  max-width: 100%;
  margin: 0 auto;
}

.video-player-inner {
  position: relative;
  width: 100%;
  padding-top: 56.25%;
  background: linear-gradient(135deg, #1a1a1a, #2d2d2d);
  border-radius: var(--radius);
  overflow: hidden;
}

.player-play-btn {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  width: 80px;
  height: 80px;
  background: rgba(255,255,255,0.9);
  border: none;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 16px rgba(0,0,0,0.3);
  transition: all 0.3s ease;
}

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

.player-play-icon {
  font-size: 2rem;
  color: var(--primary-color);
  margin-left: 4px;
}

.video-detail-header h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  color: var(--text-color);
}

.video-basic-info {
  background: white;
  padding: 1.5rem;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  margin-bottom: 2rem;
}

.video-basic-info h2 {
  font-size: 1.5rem;
  margin-bottom: 1rem;
  color: var(--text-color);
}

.info-row {
  display: flex;
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--border-color);
}

.info-row:last-child {
  border-bottom: none;
}

.info-label {
  font-weight: 600;
  min-width: 100px;
  color: #666;
}

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

.content-module {
  background: white;
  padding: 1.5rem;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  margin-bottom: 2rem;
}

.content-module h2 {
  font-size: 1.5rem;
  margin-bottom: 1rem;
  color: var(--text-color);
}

.content-module p {
  line-height: 1.8;
  color: #333;
  margin-bottom: 0.75rem;
}

.video-related-section {
  background: white;
  padding: 1.5rem;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.video-related-section h2 {
  font-size: 1.5rem;
  margin-bottom: 1.5rem;
  color: var(--text-color);
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 1rem;
}

.video-card--related {
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.site-footer {
  background: #2D2D2D;
  color: white;
  padding: 2rem 0;
  margin-top: 4rem;
  text-align: center;
}

.site-footer p {
  font-size: 0.875rem;
  opacity: 0.8;
}

@media (max-width: 768px) {
  .site-header .container {
    flex-direction: column;
    gap: 0.75rem;
  }

  .site-logo {
    font-size: 1.25rem;
  }

  .site-nav {
    gap: 0.5rem;
    font-size: 0.875rem;
  }

  .site-nav a {
    font-size: 0.875rem;
    padding: 0.4rem 0.5rem;
  }

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

  .video-cover {
    padding-top: 150%;
  }

  .video-title {
    font-size: 0.95rem;
  }

  .video-one-line {
    font-size: 0.8rem;
  }

  .related-grid {
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  }

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

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

  .video-detail-header h1 {
    font-size: 1.75rem;
  }

  .page-header h1 {
    font-size: 1.5rem;
  }
}

@media (max-width: 480px) {
  .site-nav {
    gap: 0.25rem;
  }

  .site-nav a {
    font-size: 0.75rem;
    padding: 0.3rem 0.4rem;
  }
}