/* 基础样式 */
* { box-sizing: border-box; }
body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: #333;
  line-height: 1.8;
}

/* 头部 */
header {
  background: rgba(255, 255, 255, 0.95);
  padding: 1rem 2rem;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  position: sticky;
  top: 0;
  z-index: 100;
}
.logo {
  font-size: 1.8rem;
  font-weight: bold;
  color: #667eea;
  margin-bottom: 0.5rem;
}
nav ul {
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-wrap: nowrap;
  justify-content: space-between;
  align-items: center;
  gap: 0.5rem;
}
nav ul li {
  flex: 1 1 0;
  min-width: 0;
}
nav a {
  text-decoration: none;
  color: #555;
  font-weight: 500;
  display: block;
  text-align: center;
  padding: 0.5rem;
  border-radius: 4px;
  transition: all 0.3s ease;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
nav a:hover {
  background: #667eea;
  color: white;
  transform: translateY(-2px);
}

/* 主体 */
main {
  max-width: 1200px;
  margin: 2rem auto;
  padding: 0 1rem;
  background: white;
  border-radius: 12px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.1);
}

/* 区块 */
section {
  padding: 2rem;
  margin-bottom: 2rem;
}
h1 {
  font-size: 2rem;
  color: #667eea;
  margin-bottom: 1rem;
  border-bottom: 3px solid #667eea;
  padding-bottom: 0.5rem;
}
h2 {
  font-size: 1.5rem;
  color: #555;
  margin: 1.5rem 0 1rem;
}
.intro, .topic-intro {
  color: #666;
  line-height: 2;
  margin-bottom: 1.5rem;
}

/* 卡片网格 */
.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
}
.video-card {
  background: #f9f9f9;
  padding: 1.5rem;
  border-radius: 8px;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.video-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 6px 20px rgba(102, 126, 234, 0.3);
}
.video-card h3 {
  font-size: 1.2rem;
  margin: 0 0 0.5rem;
}
.video-card h3 a {
  color: #333;
  text-decoration: none;
}
.video-card h3 a:hover {
  color: #667eea;
}
.meta {
  color: #999;
  font-size: 0.9rem;
  margin: 0.5rem 0;
}
.oneline {
  color: #666;
  font-size: 0.95rem;
}

/* 列表 */
.video-list, .top-list, .topic-list, .latest-list {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}
.video-item, .topic-item, .latest-item {
  background: #f9f9f9;
  padding: 1.5rem;
  border-radius: 8px;
  border-left: 4px solid #667eea;
}
.video-item h3, .topic-item h3, .latest-item h3 {
  margin: 0 0 0.5rem;
  font-size: 1.2rem;
}
.video-item h3 a, .topic-item h3 a, .latest-item h3 a {
  color: #333;
  text-decoration: none;
}
.video-item h3 a:hover, .topic-item h3 a:hover, .latest-item h3 a:hover {
  color: #667eea;
}

/* 排行榜 */
.top-item {
  display: flex;
  gap: 1.5rem;
  background: #f9f9f9;
  padding: 1.5rem;
  border-radius: 8px;
  align-items: flex-start;
}
.rank {
  flex-shrink: 0;
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, #667eea, #764ba2);
  color: white;
  font-size: 1.5rem;
  font-weight: bold;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
}
.top-item .content {
  flex: 1;
}
.tags {
  color: #667eea;
  font-size: 0.9rem;
  margin: 0.5rem 0;
}
.recommend {
  color: #666;
  line-height: 1.8;
}

/* 最新列表 */
.latest-item {
  display: flex;
  gap: 1rem;
}
.date {
  flex-shrink: 0;
  font-size: 0.9rem;
  color: #999;
  padding: 0.5rem;
  background: #eee;
  border-radius: 4px;
  text-align: center;
  min-width: 100px;
}
.latest-item .content {
  flex: 1;
}

/* 分组 */
.year-group {
  margin-bottom: 2rem;
}
.year-group h2 {
  background: #667eea;
  color: white;
  padding: 0.5rem 1rem;
  border-radius: 4px;
  display: inline-block;
}

/* 入口卡片 */
.entry-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
}
.entry-card {
  background: linear-gradient(135deg, #667eea, #764ba2);
  color: white;
  padding: 2rem;
  border-radius: 8px;
  text-align: center;
}
.entry-card h3 a {
  color: white;
  text-decoration: none;
  font-size: 1.3rem;
}
.entry-card p {
  margin-top: 0.5rem;
  opacity: 0.9;
}

/* 详情页 */
.detail {
  padding: 2rem;
}
.basic-info ul {
  list-style: none;
  padding: 0;
}
.basic-info li {
  padding: 0.5rem 0;
  border-bottom: 1px solid #eee;
}
.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 1.5rem;
}
.related-card {
  background: #f9f9f9;
  padding: 1rem;
  border-radius: 8px;
  border-left: 3px solid #667eea;
}
.related-card h3 {
  margin: 0 0 0.5rem;
  font-size: 1.1rem;
}
.related-card h3 a {
  color: #333;
  text-decoration: none;
}
.related-card h3 a:hover {
  color: #667eea;
}

/* 底部 */
footer {
  background: rgba(255, 255, 255, 0.95);
  padding: 2rem;
  margin-top: 2rem;
  text-align: center;
  color: #666;
}
footer nav {
  margin-bottom: 1rem;
}

/* 响应式 */
@media (max-width: 768px) {
  header { padding: 1rem; }
  .logo { font-size: 1.5rem; }
  nav a {
    font-size: 0.85rem;
    padding: 0.4rem 0.2rem;
  }
  main { margin: 1rem auto; }
  section { padding: 1rem; }
  h1 { font-size: 1.5rem; }
  .video-grid { grid-template-columns: 1fr; }
  .top-item { flex-direction: column; }
  .rank { width: 40px; height: 40px; font-size: 1.2rem; }
  .latest-item { flex-direction: column; }
}