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

:root {
  --color-primary: #007bff;
  --color-text: #333;
  --color-bg: #fff;
  --color-border: #ddd;
  --spacing: 8px;
}

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 calc(var(--spacing) * 2);
}

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

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 calc(var(--spacing) * 2);
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.logo {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-primary);
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: calc(var(--spacing) * 3);
}

.nav-links a {
  color: var(--color-text);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s;
}

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

.hero-section {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: calc(var(--spacing) * 10) calc(var(--spacing) * 2);
  text-align: center;
}

.hero-title {
  font-size: 32px;
  margin-bottom: calc(var(--spacing) * 2);
  font-weight: 700;
}

.hero-desc {
  font-size: 18px;
  opacity: 0.95;
  max-width: 800px;
  margin: 0 auto;
}

.intro-section {
  padding: calc(var(--spacing) * 6) 0;
  background: #f8f9fa;
}

.intro-text {
  font-size: 16px;
  line-height: 1.8;
  max-width: 900px;
  margin: 0 auto;
}

.video-section {
  padding: calc(var(--spacing) * 6) 0;
}

.section-title {
  font-size: 28px;
  margin-bottom: calc(var(--spacing) * 4);
  font-weight: 700;
}

.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: calc(var(--spacing) * 3);
}

.video-card {
  background: white;
  border-radius: 8px;
  overflow: hidden;
  transition: transform 0.2s, box-shadow 0.2s;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}

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

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

.video-cover {
  position: relative;
  width: 100%;
  padding-top: 56.25%;
  overflow: hidden;
  background: #f0f0f0;
}

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

.video-info {
  padding: calc(var(--spacing) * 2);
}

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

.video-meta {
  font-size: 14px;
  color: #666;
  margin-bottom: var(--spacing);
}

.video-one-line {
  font-size: 14px;
  color: #666;
  line-height: 1.5;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.main-footer {
  background: #2c3e50;
  color: white;
  text-align: center;
  padding: calc(var(--spacing) * 4) calc(var(--spacing) * 2);
  margin-top: calc(var(--spacing) * 8);
}

.list-page {
  padding: calc(var(--spacing) * 4) 0;
  min-height: 70vh;
}

.page-header {
  margin-bottom: calc(var(--spacing) * 4);
}

.page-header h1 {
  font-size: 32px;
  font-weight: 700;
}

.layout-with-sidebar {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: calc(var(--spacing) * 4);
}

.layout__side--filters {
  background: #f8f9fa;
  padding: calc(var(--spacing) * 3);
  border-radius: 8px;
}

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

.top-item {
  display: flex;
  gap: calc(var(--spacing) * 2);
  padding: calc(var(--spacing) * 2);
  border-bottom: 1px solid var(--color-border);
  align-items: center;
}

.top-rank {
  font-size: 24px;
  font-weight: 700;
  color: var(--color-primary);
  min-width: 40px;
}

.top-cover {
  width: 120px;
  height: 68px;
  border-radius: 4px;
  overflow: hidden;
  flex-shrink: 0;
}

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

.top-info {
  flex: 1;
}

.top-info h3 {
  margin-bottom: var(--spacing);
}

.top-info a {
  color: inherit;
  text-decoration: none;
}

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

.group {
  margin-bottom: calc(var(--spacing) * 6);
}

.group-title {
  font-size: 24px;
  margin-bottom: calc(var(--spacing) * 3);
  padding-bottom: calc(var(--spacing) * 2);
  border-bottom: 2px solid var(--color-primary);
}

.detail-page {
  padding-bottom: calc(var(--spacing) * 6);
}

.video-player-section {
  background: #000;
  margin-bottom: calc(var(--spacing) * 4);
}

.video-player {
  max-width: 1200px;
  margin: 0 auto;
}

.video-player-inner {
  position: relative;
  width: 100%;
  padding-top: 56.25%;
  background: #000;
  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: all 0.3s;
}

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

.player-play-icon {
  font-size: 32px;
  color: #000;
}

.detail-header {
  margin-bottom: calc(var(--spacing) * 3);
}

.detail-header h1 {
  font-size: 36px;
  font-weight: 700;
}

.detail-info, .detail-module {
  background: white;
  padding: calc(var(--spacing) * 3);
  border-radius: 8px;
  margin-bottom: calc(var(--spacing) * 3);
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}

.detail-info h2, .detail-module h2 {
  font-size: 24px;
  margin-bottom: calc(var(--spacing) * 2);
  color: var(--color-primary);
}

.info-list {
  display: grid;
  grid-template-columns: 100px 1fr;
  gap: calc(var(--spacing) * 2);
}

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

.tags-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing);
}

.tag {
  display: inline-block;
  padding: calc(var(--spacing) / 2) calc(var(--spacing) * 2);
  background: #f0f0f0;
  border-radius: 16px;
  font-size: 14px;
}

.related-section {
  margin-top: calc(var(--spacing) * 6);
}

.related-section h2 {
  font-size: 28px;
  margin-bottom: calc(var(--spacing) * 3);
}

@media (max-width: 768px) {
  .nav-links {
    gap: calc(var(--spacing) * 2);
    font-size: 14px;
  }

  .nav-container {
    padding: 0 calc(var(--spacing));
  }

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

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

  .video-grid {
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: calc(var(--spacing) * 2);
  }

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

  .layout-with-sidebar {
    grid-template-columns: 1fr;
  }

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

  .info-list {
    grid-template-columns: 80px 1fr;
  }
}

.ui-style-0 { --color-primary: #ff6b6b; }
.ui-style-1 { --color-primary: #ee5a6f; }
.ui-style-2 { --color-primary: #f39c12; }
.ui-style-3 { --color-primary: #e74c3c; }
.ui-style-4 { --color-primary: #c0392b; }
.ui-style-5 { --color-primary: #8e44ad; }
.ui-style-6 { --color-primary: #3498db; }
.ui-style-7 { --color-primary: #2980b9; }
.ui-style-8 { --color-primary: #1abc9c; }
.ui-style-9 { --color-primary: #16a085; }
.ui-style-10 { --color-primary: #27ae60; }
.ui-style-11 { --color-primary: #0099FF; }
.ui-style-12 { --color-primary: #FF6700; }
.ui-style-13 { --color-primary: #00A1D6; }
.ui-style-14 { --color-primary: #2563eb; }