/* 基础重置 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  line-height: 1.6;
  color: #333;
  background: #f5f5f5;
}

a {
  color: #0066cc;
  text-decoration: none;
  transition: color 0.3s;
}

a:hover {
  color: #004499;
  text-decoration: underline;
}

img {
  max-width: 100%;
  height: auto;
}

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

/* 顶部导航 */
.top-nav {
  background: #ffffff;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.nav-container {
  display: flex;
  flex-wrap: nowrap;
  justify-content: space-between;
  align-items: center;
  padding: 15px 20px;
}

.nav-logo {
  font-size: 1.5rem;
  font-weight: bold;
  color: #0066cc;
  white-space: nowrap;
  margin-right: 20px;
}

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

.nav-menu li {
  flex-shrink: 0;
}

.nav-menu a {
  display: block;
  padding: 8px 16px;
  color: #333;
  white-space: nowrap;
  border-radius: 4px;
  transition: background 0.3s;
}

.nav-menu a:hover,
.nav-menu a.active {
  background: #0066cc;
  color: #fff;
  text-decoration: none;
}

/* 页面主体 */
.page-header {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: #fff;
  padding: 60px 0;
  text-align: center;
}

.page-header h1 {
  font-size: 2.5rem;
  margin-bottom: 15px;
  line-height: 1.2;
}

.page-header p {
  font-size: 1.1rem;
  opacity: 0.9;
  max-width: 800px;
  margin: 0 auto;
}

.main-content {
  padding: 40px 0;
}

/* 段落区块 */
.intro-section {
  background: #fff;
  padding: 30px;
  margin-bottom: 30px;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.intro-section h2 {
  font-size: 1.8rem;
  margin-bottom: 15px;
  color: #333;
}

.intro-section p {
  line-height: 1.8;
  color: #555;
}

/* 列表模块 */
.content-section {
  margin-bottom: 50px;
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}

.section-title {
  font-size: 1.8rem;
  color: #333;
  padding-bottom: 10px;
  border-bottom: 3px solid #0066cc;
}

.section-link {
  font-size: 0.95rem;
  color: #0066cc;
}

.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 25px;
}

.video-card {
  background: #fff;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  transition: transform 0.3s, box-shadow 0.3s;
}

.video-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 4px 16px rgba(0,0,0,0.15);
}

.video-card-body {
  padding: 20px;
}

.video-title {
  font-size: 1.2rem;
  font-weight: bold;
  margin-bottom: 10px;
  color: #333;
}

.video-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 10px;
  font-size: 0.9rem;
  color: #666;
}

.video-meta span {
  display: inline-block;
}

.video-oneline {
  color: #555;
  margin-bottom: 10px;
  font-size: 0.95rem;
  line-height: 1.5;
}

.video-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 10px;
}

.tag {
  display: inline-block;
  padding: 4px 10px;
  background: #e3f2fd;
  color: #0066cc;
  border-radius: 4px;
  font-size: 0.85rem;
}

/* 列表视图 */
.video-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.video-list-item {
  background: #fff;
  padding: 20px;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  transition: box-shadow 0.3s;
}

.video-list-item:hover {
  box-shadow: 0 4px 16px rgba(0,0,0,0.15);
}

.video-list-item .video-title {
  margin-bottom: 12px;
}

.rank-number {
  display: inline-block;
  width: 32px;
  height: 32px;
  line-height: 32px;
  text-align: center;
  background: #0066cc;
  color: #fff;
  border-radius: 4px;
  font-weight: bold;
  margin-right: 10px;
}

/* 详情页 */
.detail-container {
  max-width: 900px;
  margin: 0 auto;
  padding: 40px 20px;
}

.detail-header {
  background: #fff;
  padding: 30px;
  border-radius: 8px;
  margin-bottom: 30px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.detail-title {
  font-size: 2.2rem;
  margin-bottom: 20px;
  color: #333;
  line-height: 1.3;
}

.detail-info {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 15px;
  margin-bottom: 20px;
  padding: 20px;
  background: #f9f9f9;
  border-radius: 6px;
}

.info-item {
  display: flex;
  gap: 8px;
}

.info-label {
  font-weight: bold;
  color: #666;
}

.info-value {
  color: #333;
}

.detail-section {
  background: #fff;
  padding: 30px;
  margin-bottom: 30px;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.detail-section h2 {
  font-size: 1.6rem;
  margin-bottom: 15px;
  color: #333;
  padding-bottom: 10px;
  border-bottom: 2px solid #0066cc;
}

.detail-section p {
  line-height: 1.8;
  color: #555;
  margin-bottom: 15px;
}

.review-box {
  background: #fffbf0;
  border-left: 4px solid #ffa000;
  padding: 15px 20px;
  margin: 15px 0;
  border-radius: 4px;
}

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

/* 页脚 */
.site-footer {
  background: #333;
  color: #fff;
  padding: 30px 0;
  text-align: center;
  margin-top: 50px;
}

.site-footer p {
  margin: 5px 0;
  opacity: 0.8;
}

/* 响应式 */
@media (max-width: 768px) {
  .nav-container {
    padding: 10px 15px;
  }

  .nav-logo {
    font-size: 1.2rem;
    margin-right: 10px;
  }

  .nav-menu {
    gap: 5px;
  }

  .nav-menu a {
    padding: 6px 10px;
    font-size: 0.85rem;
  }

  .page-header h1 {
    font-size: 1.8rem;
  }

  .page-header p {
    font-size: 1rem;
  }

  .video-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .detail-title {
    font-size: 1.6rem;
  }

  .detail-info {
    grid-template-columns: 1fr;
  }

  .related-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .nav-logo {
    font-size: 1rem;
    margin-right: 5px;
  }

  .nav-menu a {
    padding: 5px 8px;
    font-size: 0.75rem;
  }

  .page-header {
    padding: 40px 0;
  }

  .page-header h1 {
    font-size: 1.5rem;
  }

  .section-title {
    font-size: 1.4rem;
  }
}

/* UI 风格变体 */
.ui-style-0 { --primary-color: #0066cc; }
.ui-style-1 { --primary-color: #2196F3; }
.ui-style-2 { --primary-color: #00897B; }
.ui-style-3 { --primary-color: #7CB342; }
.ui-style-4 { --primary-color: #FFA726; }
.ui-style-5 { --primary-color: #EF5350; }
.ui-style-6 { --primary-color: #AB47BC; }
.ui-style-7 { --primary-color: #5C6BC0; }
.ui-style-8 { --primary-color: #26A69A; }
.ui-style-9 { --primary-color: #66BB6A; }
.ui-style-10 { --primary-color: #FFA000; }
.ui-style-11 { --primary-color: #EC407A; }
.ui-style-12 { --primary-color: #8E24AA; }
.ui-style-13 { --primary-color: #3949AB; }
.ui-style-14 { --primary-color: #00ACC1; }
.ui-style-15 { --primary-color: #43A047; }