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

.hero {
  text-align: center;
  padding: 40px 20px;
  background: #fff;
  border-radius: 8px;
  margin-bottom: 30px;
}

.hero h1 {
  font-size: 28px;
  color: #1890ff;
  margin-bottom: 20px;
}

.intro {
  font-size: 16px;
  line-height: 1.8;
  color: #666;
  max-width: 800px;
  margin: 0 auto;
}

section {
  margin-bottom: 40px;
}

h2 {
  font-size: 24px;
  margin-bottom: 20px;
  padding-bottom: 10px;
  border-bottom: 2px solid #1890ff;
}

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

.video-card {
  background: #fff;
  padding: 20px;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
  transition: transform 0.3s, box-shadow 0.3s;
}

.video-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 4px 16px rgba(0,0,0,0.12);
}

.video-card h3 {
  font-size: 18px;
  margin-bottom: 10px;
  color: #333;
}

.video-card .meta {
  font-size: 13px;
  color: #999;
  margin-bottom: 10px;
}

.video-card .oneline {
  font-size: 14px;
  color: #666;
  line-height: 1.6;
}

.more-link {
  text-align: center;
  margin-top: 20px;
}

.more-link a {
  display: inline-block;
  padding: 10px 30px;
  background: #1890ff;
  color: #fff;
  border-radius: 4px;
  font-size: 16px;
  transition: background 0.3s;
}

.more-link a:hover {
  background: #40a9ff;
  text-decoration: none;
}

.topic-links {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 20px;
}

.topic-card {
  display: block;
  background: #fff;
  padding: 30px;
  border-radius: 8px;
  text-align: center;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
  transition: transform 0.3s, box-shadow 0.3s;
}

.topic-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 4px 16px rgba(0,0,0,0.12);
  text-decoration: none;
}

.topic-card h3 {
  font-size: 20px;
  margin-bottom: 10px;
  color: #1890ff;
}

.topic-card p {
  color: #666;
  font-size: 14px;
}

.page-header {
  background: #fff;
  padding: 30px;
  border-radius: 8px;
  margin-bottom: 30px;
}

.page-header h1 {
  font-size: 26px;
  color: #1890ff;
  margin-bottom: 15px;
}

.video-list {
  background: #fff;
  padding: 20px;
  border-radius: 8px;
}

.list-item {
  display: flex;
  gap: 15px;
  padding: 20px;
  border-bottom: 1px solid #f0f0f0;
  align-items: flex-start;
}

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

.rank {
  font-size: 24px;
  font-weight: bold;
  color: #ff4d4f;
  min-width: 40px;
  text-align: center;
}

.date {
  font-size: 14px;
  color: #999;
  min-width: 60px;
}

.item-content {
  flex: 1;
}

.item-content h3 {
  font-size: 18px;
  margin-bottom: 10px;
}

.item-content .summary {
  font-size: 14px;
  color: #666;
  line-height: 1.6;
  margin-top: 10px;
}

.tags {
  font-size: 13px;
  color: #999;
  margin-top: 8px;
}

.detail-page {
  background: #fff;
  padding: 30px;
  border-radius: 8px;
}

.detail-content h1 {
  font-size: 32px;
  color: #333;
  margin-bottom: 20px;
}

.meta-info {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  margin-bottom: 20px;
  padding: 15px;
  background: #f5f5f5;
  border-radius: 4px;
}

.meta-info span {
  font-size: 14px;
  color: #666;
}

.tag {
  display: inline-block;
  padding: 4px 12px;
  background: #e6f7ff;
  color: #1890ff;
  border-radius: 4px;
  font-size: 13px;
  margin-right: 8px;
  margin-bottom: 8px;
}

.detail-content section {
  margin-bottom: 30px;
}

.detail-content section h2 {
  font-size: 20px;
  margin-bottom: 15px;
  color: #333;
}

.detail-content section p {
  font-size: 15px;
  line-height: 1.8;
  color: #666;
}

footer {
  text-align: center;
  padding: 30px 20px;
  color: #999;
  font-size: 14px;
  border-top: 1px solid #e8e8e8;
  margin-top: 50px;
}

@media (max-width: 768px) {
  .container {
    padding: 15px;
  }

  .hero h1 {
    font-size: 22px;
  }

  .intro {
    font-size: 14px;
  }

  .video-grid {
    grid-template-columns: 1fr;
    gap: 15px;
  }

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

  .meta-info {
    flex-direction: column;
    gap: 10px;
  }
}