body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: #f5f5f5;
  color: #333;
  line-height: 1.6;
}

* {
  box-sizing: border-box;
}

.header {
  background: #fff;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  position: sticky;
  top: 0;
  z-index: 100;
}

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

.logo {
  font-size: 24px;
  font-weight: bold;
  color: #e74c3c;
  text-decoration: none;
  padding: 15px 0;
  display: inline-block;
}

.nav {
  display: flex;
  flex-wrap: nowrap;
  justify-content: space-between;
  align-items: center;
  border-top: 1px solid #eee;
  padding: 0;
  margin: 0;
  list-style: none;
}

.nav li {
  flex: 1 1 0;
  min-width: 0;
  text-align: center;
  margin: 0;
  padding: 0;
}

.nav a {
  display: block;
  padding: 12px 8px;
  color: #555;
  text-decoration: none;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  transition: all 0.3s;
}

.nav a:hover {
  background: #f8f9fa;
  color: #e74c3c;
}

@media (max-width: 767px) {
  .nav a {
    padding: 10px 4px;
    font-size: 13px;
  }
  
  .logo {
    font-size: 20px;
    padding: 12px 0;
  }
}

.main {
  padding: 30px 0;
  min-height: 60vh;
}

.page-title {
  font-size: 28px;
  margin: 0 0 20px;
  color: #222;
  font-weight: 700;
}

.intro {
  background: #fff;
  padding: 25px;
  border-radius: 8px;
  margin-bottom: 30px;
  box-shadow: 0 2px 12px rgba(0,0,0,0.08);
  line-height: 1.8;
}

.section {
  background: #fff;
  padding: 25px;
  border-radius: 8px;
  margin-bottom: 25px;
  box-shadow: 0 2px 12px rgba(0,0,0,0.08);
}

.section-title {
  font-size: 22px;
  margin: 0 0 20px;
  color: #333;
  font-weight: 600;
  border-left: 4px solid #e74c3c;
  padding-left: 12px;
}

.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
  margin-top: 20px;
}

.video-card {
  background: #fafafa;
  border-radius: 6px;
  padding: 18px;
  transition: all 0.3s;
  border: 1px solid #eee;
}

.video-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 4px 16px rgba(0,0,0,0.15);
  border-color: #e74c3c;
}

.video-card h3 {
  margin: 0 0 10px;
  font-size: 18px;
  color: #222;
}

.video-card h3 a {
  color: #222;
  text-decoration: none;
}

.video-card h3 a:hover {
  color: #e74c3c;
}

.video-meta {
  font-size: 13px;
  color: #888;
  margin: 8px 0;
}

.video-meta span {
  margin-right: 15px;
}

.video-desc {
  font-size: 14px;
  color: #666;
  line-height: 1.6;
  margin-top: 10px;
}

.video-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.video-list li {
  padding: 15px 0;
  border-bottom: 1px solid #eee;
}

.video-list li:last-child {
  border-bottom: none;
}

.video-list .rank {
  display: inline-block;
  width: 28px;
  height: 28px;
  line-height: 28px;
  text-align: center;
  background: #666;
  color: #fff;
  border-radius: 4px;
  font-weight: bold;
  margin-right: 10px;
  font-size: 14px;
}

.video-list .rank-top {
  background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
}

.detail-header {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: #fff;
  padding: 40px 0;
  margin: -30px 0 30px;
}

.detail-title {
  font-size: 32px;
  margin: 0 0 15px;
}

.detail-meta {
  font-size: 15px;
  opacity: 0.95;
}

.detail-meta span {
  margin-right: 20px;
}

.detail-content {
  background: #fff;
  padding: 30px;
  border-radius: 8px;
  box-shadow: 0 2px 12px rgba(0,0,0,0.08);
  margin-bottom: 25px;
}

.detail-content h2 {
  font-size: 20px;
  margin: 25px 0 15px;
  color: #333;
  border-left: 4px solid #e74c3c;
  padding-left: 12px;
}

.detail-content h2:first-child {
  margin-top: 0;
}

.tags {
  margin: 15px 0;
}

.tag {
  display: inline-block;
  background: #f0f0f0;
  color: #666;
  padding: 5px 12px;
  border-radius: 15px;
  font-size: 13px;
  margin: 5px 8px 5px 0;
}

.footer {
  background: #2c3e50;
  color: #ecf0f1;
  text-align: center;
  padding: 25px 0;
  margin-top: 40px;
}

.footer p {
  margin: 8px 0;
  font-size: 14px;
}

.back-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 45px;
  height: 45px;
  background: #e74c3c;
  color: #fff;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s;
  font-size: 20px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.2);
}

.back-top.show {
  opacity: 1;
  visibility: visible;
}

.back-top:hover {
  background: #c0392b;
  transform: translateY(-3px);
}

@media (max-width: 767px) {
  .video-grid {
    grid-template-columns: 1fr;
  }
  
  .page-title {
    font-size: 24px;
  }
  
  .section-title {
    font-size: 20px;
  }
  
  .detail-title {
    font-size: 26px;
  }
  
  .intro, .section, .detail-content {
    padding: 20px;
  }
}

body.ui-style-6 {
  --primary-color: #e74c3c;
  --secondary-color: #3498db;
}