/* 全局样式 */
* { box-sizing: border-box; }
body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif; margin: 0; padding: 0; background: #f5f5f5; color: #333; line-height: 1.6; }
a { color: #667eea; text-decoration: none; transition: color 0.3s; }
a:hover { color: #764ba2; }

/* 导航栏 */
nav { background: #2c3e50; color: #fff; padding: 1rem 2rem; position: sticky; top: 0; z-index: 1000; box-shadow: 0 2px 8px rgba(0,0,0,0.1); }
nav ul { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: nowrap; justify-content: space-between; align-items: center; }
nav ul li { flex: 1 1 0; min-width: 0; text-align: center; }
nav a { color: #fff; text-decoration: none; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; display: block; padding: 0.5rem; border-radius: 4px; transition: background 0.3s; }
nav a:hover { background: #34495e; }

/* 卡片样式 */
.video-card { background: #fff; padding: 1.5rem; 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(-4px); box-shadow: 0 4px 16px rgba(0,0,0,0.12); }
.video-card h3 { margin: 0 0 0.5rem 0; font-size: 1.2rem; color: #2c3e50; }
.video-card .one-line { color: #666; margin: 0.5rem 0; line-height: 1.6; }
.video-card .meta { color: #999; font-size: 0.9rem; margin: 0.5rem 0 0 0; }

/* 列表样式 */
.video-item { padding: 1rem 0; border-bottom: 1px solid #eee; }
.video-item h4 { margin: 0 0 0.5rem 0; font-size: 1.1rem; color: #2c3e50; }
.video-item p { margin: 0; color: #666; }

/* 响应式设计 */
@media (max-width: 768px) {
  nav { padding: 0.5rem; }
  nav ul li { font-size: 0.75rem; padding: 0.25rem; }
  nav a { padding: 0.3rem; }
  header h1 { font-size: 1.5rem !important; }
  header p { font-size: 0.95rem !important; }
  main { padding: 0 0.5rem !important; }
  .video-grid { grid-template-columns: 1fr !important; }
}

/* UI 风格变体 */
.ui-style-5 { --primary-color: #667eea; --secondary-color: #764ba2; }