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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Microsoft YaHei', 'Hiragino Sans GB', sans-serif;
  line-height: 1.8;
  color: #333;
  background: #f5f7fa;
}

a {
  color: #3498db;
  text-decoration: none;
  transition: color 0.3s ease;
}

a:hover {
  color: #2980b9;
}

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

/* Header */
.header {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 1.5rem 0;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.logo {
  font-size: 1.8rem;
  font-weight: bold;
  color: white;
  text-decoration: none;
  letter-spacing: 1px;
}

.nav {
  display: flex;
  list-style: none;
  gap: 2rem;
  flex-wrap: nowrap;
  align-items: center;
}

.nav li {
  list-style: none;
}

.nav a {
  color: white;
  text-decoration: none;
  font-weight: 500;
  white-space: nowrap;
  padding: 0.5rem 1rem;
  border-radius: 5px;
  transition: background 0.3s ease;
}

.nav a:hover {
  background: rgba(255, 255, 255, 0.2);
}

/* Main Content */
.main {
  min-height: calc(100vh - 300px);
  padding: 2rem 0;
}

/* Hero Section */
.hero {
  text-align: center;
  padding: 3rem 0 2rem;
}

.page-title {
  font-size: 2.5rem;
  color: #2c3e50;
  margin-bottom: 1rem;
  font-weight: 700;
}

/* Intro Section */
.intro-section {
  background: white;
  padding: 2rem;
  border-radius: 10px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
  margin-bottom: 3rem;
}

.intro-content p {
  margin-bottom: 1rem;
  color: #555;
  font-size: 1.05rem;
}

.page-intro {
  background: white;
  padding: 2rem;
  border-radius: 10px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
  margin-bottom: 2rem;
}

.page-intro p {
  margin-bottom: 1rem;
  color: #555;
}

.topic-intro {
  border-left: 4px solid #667eea;
  padding-left: 2rem;
}

/* Section Styles */
.section-title {
  font-size: 1.8rem;
  color: #2c3e50;
  margin-bottom: 1.5rem;
  padding-bottom: 0.5rem;
  border-bottom: 3px solid #667eea;
  font-weight: 600;
}

.hot-section,
.entrance-section,
.latest-section {
  margin-bottom: 3rem;
}

/* Video Grid */
.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.video-card {
  background: white;
  padding: 1.5rem;
  border-radius: 10px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.video-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 5px 20px rgba(0, 0, 0, 0.15);
}

.video-title {
  font-size: 1.2rem;
  margin-bottom: 0.8rem;
  color: #2c3e50;
}

.video-title a {
  color: #2c3e50;
}

.video-title a:hover {
  color: #667eea;
}

.video-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.meta-item {
  background: #f0f0f0;
  padding: 0.25rem 0.75rem;
  border-radius: 15px;
  font-size: 0.85rem;
  color: #666;
}

.tag-item {
  background: #e8f4f8;
  color: #3498db;
  padding: 0.25rem 0.75rem;
  border-radius: 15px;
  font-size: 0.85rem;
}

.video-desc,
.video-brief {
  color: #666;
  line-height: 1.6;
  margin-bottom: 1rem;
}

.read-more {
  display: inline-block;
  color: #667eea;
  font-weight: 500;
  padding: 0.5rem 1rem;
  border: 1px solid #667eea;
  border-radius: 5px;
  transition: all 0.3s ease;
}

.read-more:hover {
  background: #667eea;
  color: white;
}

/* Entrance Grid */
.entrance-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
}

.entrance-card {
  background: white;
  padding: 2rem;
  border-radius: 10px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
  transition: transform 0.3s ease;
}

.entrance-card:hover {
  transform: translateY(-5px);
}

.entrance-card h3 {
  font-size: 1.5rem;
  margin-bottom: 1rem;
  color: #2c3e50;
}

.entrance-card h3 a {
  color: #667eea;
}

.entrance-card p {
  color: #666;
  line-height: 1.8;
}

/* Video List */
.video-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.video-list-item {
  background: white;
  padding: 1.5rem;
  border-radius: 10px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
  transition: box-shadow 0.3s ease;
}

.video-list-item:hover {
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.more-link {
  text-align: center;
  margin-top: 2rem;
}

.more-link a {
  display: inline-block;
  padding: 0.75rem 2rem;
  background: #667eea;
  color: white;
  border-radius: 25px;
  font-weight: 500;
  transition: background 0.3s ease;
}

.more-link a:hover {
  background: #764ba2;
}

/* Year Section */
.year-section {
  margin-bottom: 3rem;
}

.year-title {
  font-size: 1.5rem;
  color: #667eea;
  margin-bottom: 1.5rem;
  padding: 0.5rem 1rem;
  background: white;
  border-left: 4px solid #667eea;
  border-radius: 5px;
}

/* Top List */
.top-list {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.top-item {
  display: flex;
  gap: 1.5rem;
  background: white;
  padding: 1.5rem;
  border-radius: 10px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
  transition: transform 0.3s ease;
}

.top-item:hover {
  transform: translateX(5px);
}

.top-rank {
  flex-shrink: 0;
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  font-weight: bold;
  border-radius: 10px;
}

.top-content {
  flex: 1;
}

.top-reason {
  color: #666;
  line-height: 1.8;
  margin-top: 0.5rem;
}

/* Topic List */
.topic-list {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.topic-item {
  background: white;
  padding: 2rem;
  border-radius: 10px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
}

.topic-content {
  margin-top: 1rem;
  color: #555;
}

.topic-detail {
  margin: 0.5rem 0;
  line-height: 1.8;
}

.topic-review {
  margin-top: 1rem;
  padding: 1rem;
  background: #f8f9fa;
  border-left: 3px solid #667eea;
  border-radius: 5px;
}

/* Latest List */
.latest-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.latest-item {
  display: flex;
  gap: 1.5rem;
  background: white;
  padding: 1.5rem;
  border-radius: 10px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.latest-date {
  flex-shrink: 0;
  width: 100px;
  color: #667eea;
  font-weight: 600;
  font-size: 0.95rem;
}

.latest-content {
  flex: 1;
}

.latest-brief {
  color: #666;
  margin-top: 0.5rem;
}

/* Detail Page */
.detail-article {
  background: white;
  padding: 3rem;
  border-radius: 10px;
  box-shadow: 0 2px 15px rgba(0, 0, 0, 0.08);
}

.article-title {
  font-size: 2rem;
  color: #2c3e50;
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 3px solid #667eea;
}

.info-section,
.oneline-section,
.summary-section,
.review-section,
.related-section {
  margin-bottom: 2.5rem;
}

.info-section h2,
.oneline-section h2,
.summary-section h2,
.review-section h2,
.related-section h2 {
  font-size: 1.5rem;
  color: #2c3e50;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid #f0f0f0;
}

.info-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}

.info-item {
  padding: 0.5rem 0;
  color: #555;
}

.info-item strong {
  color: #2c3e50;
}

.oneline-text {
  font-size: 1.2rem;
  color: #667eea;
  line-height: 1.8;
  padding: 1rem;
  background: #f8f9fa;
  border-left: 4px solid #667eea;
  border-radius: 5px;
}

.summary-text,
.review-text {
  color: #555;
  line-height: 2;
  font-size: 1.05rem;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 1.5rem;
  margin-top: 1rem;
}

.related-card {
  padding: 1.5rem;
  background: #f8f9fa;
  border-radius: 8px;
  transition: background 0.3s ease;
}

.related-card:hover {
  background: #e9ecef;
}

.related-card h3 {
  font-size: 1.1rem;
  margin-bottom: 0.8rem;
  color: #2c3e50;
}

.related-card h3 a {
  color: #2c3e50;
}

.related-card h3 a:hover {
  color: #667eea;
}

.related-brief {
  color: #666;
  font-size: 0.95rem;
  line-height: 1.6;
}

/* Footer */
.footer {
  background: #2c3e50;
  color: white;
  padding: 2rem 0;
  margin-top: 3rem;
}

.footer-nav {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 2rem;
  margin-bottom: 1rem;
}

.footer-nav a {
  color: white;
  text-decoration: none;
  transition: color 0.3s ease;
}

.footer-nav a:hover {
  color: #667eea;
}

.copyright {
  text-align: center;
  color: #bdc3c7;
  font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 768px) {
  .header-content {
    flex-direction: column;
    gap: 0.5rem;
  }

  .logo {
    font-size: 1.5rem;
  }

  .nav {
    width: 100%;
    justify-content: space-between;
    gap: 0;
    flex-wrap: nowrap;
    margin: 0;
  }

  .nav li {
    flex: 1 1 0;
    min-width: 0;
    text-align: center;
    margin: 0;
    padding: 0;
  }

  .nav a {
    font-size: 0.85rem;
    padding: 0.4rem 0.3rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    display: block;
  }

  .page-title {
    font-size: 1.8rem;
  }

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

  .detail-article {
    padding: 1.5rem;
  }

  .article-title {
    font-size: 1.5rem;
  }

  .top-item {
    flex-direction: column;
    align-items: flex-start;
  }

  .latest-item {
    flex-direction: column;
  }

  .latest-date {
    width: auto;
  }

  .footer-nav {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .nav a {
    font-size: 0.75rem;
    padding: 0.3rem 0.2rem;
  }

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

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

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

/* Back to Top Button */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 50px;
  height: 50px;
  background: #667eea;
  color: white;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  display: none;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
  transition: all 0.3s ease;
  z-index: 999;
}

.back-to-top:hover {
  background: #764ba2;
  transform: translateY(-3px);
}

.back-to-top.show {
  display: flex;
}