/* 全局样式 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
}

/* 导航栏 */
nav {
  background: #2c3e50;
  color: white;
  padding: 1rem;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

nav .container {
  display: flex;
  flex-wrap: nowrap;
  justify-content: space-between;
  align-items: center;
}

nav a {
  color: white;
  text-decoration: none;
  padding: 0.5rem 1rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  flex: 1 1 0;
  min-width: 0;
  text-align: center;
  transition: background 0.3s;
  border-radius: 4px;
}

nav a:hover {
  background: rgba(255,255,255,0.1);
}

/* 移动端导航 */
@media (max-width: 768px) {
  nav .container {
    flex-wrap: nowrap;
    overflow-x: hidden;
  }

  nav a {
    font-size: 0.85rem;
    padding: 0.4rem 0.5rem;
  }
}

/* 卡片样式 */
.video-card, .list-card {
  transition: transform 0.3s, box-shadow 0.3s;
}

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

/* 响应式网格 */
.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
}

@media (max-width: 768px) {
  .video-grid {
    grid-template-columns: 1fr;
  }
}

/* UI风格变体 */
body.ui-style-5 {
  background: linear-gradient(to bottom, #f5f5f5 0%, #e8e8e8 100%);
}

body.ui-style-5 nav {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

body.ui-style-5 .video-card:hover {
  border-left: 4px solid #667eea;
}

/* 详情页样式 */
.detail-page h1 {
  border-bottom: 3px solid #3498db;
  padding-bottom: 0.5rem;
}

.info-grid {
  background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
}

.related-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 8px rgba(0,0,0,0.2);
  border-color: #3498db;
}

/* 辅助类 */
.text-center { text-align: center; }
.mb-1 { margin-bottom: 1rem; }
.mb-2 { margin-bottom: 2rem; }
.mt-2 { margin-top: 2rem; }