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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Microsoft YaHei', sans-serif;
  line-height: 1.6;
  color: #333;
  background: #f5f5f5;
}

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

header {
  background: #fff;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px 20px;
  max-width: 1200px;
  margin: 0 auto;
}

.logo {
  font-size: 24px;
  font-weight: bold;
  color: #2c5282;
  text-decoration: none;
}

nav {
  display: flex;
  flex-wrap: nowrap;
  align-items: center;
  gap: 25px;
}

nav a {
  color: #555;
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.3s;
  font-size: 15px;
}

nav a:hover {
  color: #2c5282;
}

main {
  padding: 40px 0;
  min-height: calc(100vh - 200px);
}

h1 {
  font-size: 32px;
  color: #1a202c;
  margin-bottom: 20px;
  line-height: 1.3;
}

h2 {
  font-size: 24px;
  color: #2d3748;
  margin: 30px 0 20px;
  padding-bottom: 10px;
  border-bottom: 2px solid #2c5282;
}

.intro {
  background: #fff;
  padding: 30px;
  margin-bottom: 40px;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  line-height: 1.8;
}

.section {
  margin-bottom: 50px;
}

.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 25px;
  margin-top: 20px;
}

.video-card {
  background: #fff;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  transition: transform 0.3s, box-shadow 0.3s;
}

.video-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 4px 16px rgba(0,0,0,0.15);
}

.video-card-content {
  padding: 20px;
}

.video-title {
  font-size: 18px;
  font-weight: bold;
  color: #1a202c;
  margin-bottom: 10px;
  text-decoration: none;
  display: block;
}

.video-title:hover {
  color: #2c5282;
}

.video-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 10px;
  font-size: 13px;
  color: #666;
}

.video-meta span {
  background: #e2e8f0;
  padding: 3px 10px;
  border-radius: 12px;
}

.video-oneline {
  font-size: 14px;
  color: #4a5568;
  line-height: 1.6;
}

.detail-header {
  background: #fff;
  padding: 30px;
  margin-bottom: 30px;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.detail-meta {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 15px;
  margin: 20px 0;
  padding: 20px;
  background: #f7fafc;
  border-radius: 8px;
}

.detail-meta-item {
  font-size: 14px;
}

.detail-meta-item strong {
  color: #2d3748;
  margin-right: 8px;
}

.detail-content {
  background: #fff;
  padding: 30px;
  margin-bottom: 30px;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  line-height: 1.8;
}

.detail-content h2 {
  margin-top: 30px;
}

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

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 15px 0;
}

.tag {
  background: #3182ce;
  color: #fff;
  padding: 5px 12px;
  border-radius: 15px;
  font-size: 13px;
}

.related-videos {
  background: #fff;
  padding: 30px;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

footer {
  background: #2d3748;
  color: #cbd5e0;
  padding: 30px 0;
  margin-top: 60px;
  text-align: center;
}

.list-intro {
  background: #fff;
  padding: 25px;
  margin-bottom: 30px;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  line-height: 1.8;
}

.video-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.video-list-item {
  background: #fff;
  padding: 25px;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  transition: transform 0.2s, box-shadow 0.2s;
}

.video-list-item:hover {
  transform: translateX(5px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.rank-number {
  display: inline-block;
  width: 32px;
  height: 32px;
  line-height: 32px;
  text-align: center;
  background: #2c5282;
  color: #fff;
  border-radius: 50%;
  font-weight: bold;
  margin-right: 15px;
}

@media (max-width: 768px) {
  .header-content {
    flex-direction: column;
    gap: 15px;
    padding: 12px 15px;
  }
  
  nav {
    width: 100%;
    display: flex;
    flex-wrap: nowrap;
    justify-content: space-between;
    align-items: center;
    gap: 8px;
    overflow: hidden;
  }
  
  nav a {
    flex: 1 1 0;
    min-width: 0;
    text-align: center;
    font-size: 13px;
    padding: 8px 5px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }
  
  h1 {
    font-size: 24px;
  }
  
  .video-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  
  .detail-meta {
    grid-template-columns: 1fr;
  }
}