/* 通用样式 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  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: rgba(255, 255, 255, 0.95);
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.nav-container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: nowrap;
}

.logo {
  font-size: 24px;
  font-weight: bold;
  color: #667eea;
  padding: 15px 0;
  white-space: nowrap;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 10px;
  flex-wrap: nowrap;
  flex: 1;
  justify-content: flex-end;
  align-items: center;
}

.nav-links li {
  flex: 0 0 auto;
}

.nav-links a {
  padding: 15px 20px;
  display: block;
  white-space: nowrap;
  font-size: 15px;
}

/* 移动端导航 - 单行不换行 */
@media (max-width: 768px) {
  .nav-container {
    padding: 0 10px;
  }

  .logo {
    font-size: 18px;
    padding: 12px 0;
    margin-right: 10px;
  }

  .nav-links {
    gap: 0;
    min-width: 0;
  }

  .nav-links li {
    flex: 1 1 0;
    min-width: 0;
  }

  .nav-links a {
    padding: 12px 5px;
    font-size: 12px;
    text-align: center;
    overflow: hidden;
    text-overflow: ellipsis;
  }
}

/* 容器 */
.container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 40px 20px;
}

/* 标题 */
h1 {
  font-size: 32px;
  margin-bottom: 20px;
  color: #fff;
  text-align: center;
}

h2 {
  font-size: 24px;
  margin: 30px 0 20px;
  color: #fff;
}

/* 介绍区域 */
.intro-section {
  background: rgba(255, 255, 255, 0.95);
  border-radius: 10px;
  padding: 30px;
  margin-bottom: 40px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

.intro-section p {
  font-size: 16px;
  line-height: 1.8;
  color: #555;
  margin-bottom: 15px;
}

/* 卡片网格 */
.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 25px;
  margin-bottom: 40px;
}

.video-card {
  background: rgba(255, 255, 255, 0.95);
  border-radius: 10px;
  padding: 25px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.1);
  transition: transform 0.3s, box-shadow 0.3s;
}

.video-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 25px rgba(0,0,0,0.15);
}

.video-card h3 {
  font-size: 20px;
  margin-bottom: 10px;
  color: #333;
}

.video-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 10px 0;
  font-size: 14px;
  color: #666;
}

.video-meta span {
  background: #f0f0f0;
  padding: 4px 10px;
  border-radius: 4px;
}

.video-oneline {
  color: #555;
  font-size: 14px;
  margin: 15px 0;
  line-height: 1.6;
}

.video-summary {
  color: #666;
  font-size: 14px;
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* 列表样式 */
.video-list {
  background: rgba(255, 255, 255, 0.95);
  border-radius: 10px;
  padding: 25px;
  margin-bottom: 40px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

.video-list-item {
  padding: 20px;
  border-bottom: 1px solid #eee;
  transition: background 0.3s;
}

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

.video-list-item:hover {
  background: #f9f9f9;
}

/* 响应式 */
@media (max-width: 768px) {
  .container {
    padding: 20px 10px;
  }

  h1 {
    font-size: 24px;
  }

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

  .intro-section {
    padding: 20px;
  }
}