:root {
  --primary-color: #e74c3c;
  --secondary-color: #3498db;
  --text-color: #333;
  --bg-color: #f5f5f5;
  --card-bg: #fff;
  --border-color: #ddd;
  --hover-color: #c0392b;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.6;
  color: var(--text-color);
  background: var(--bg-color);
}

a {
  color: var(--primary-color);
  text-decoration: none;
  transition: color 0.3s;
}

a:hover {
  color: var(--hover-color);
}

header {
  background: var(--card-bg);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.logo {
  text-align: center;
  padding: 1.5rem 1rem 1rem;
}

.logo a {
  font-size: 1.8rem;
  font-weight: bold;
  color: var(--primary-color);
}

nav {
  display: flex;
  flex-wrap: nowrap;
  justify-content: space-between;
  align-items: center;
  padding: 0 1rem 1rem;
}

nav a {
  flex: 1 1 0;
  min-width: 0;
  text-align: center;
  color: var(--text-color);
  padding: 0.5rem 0.5rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  font-size: 0.95rem;
  border-bottom: 2px solid transparent;
}

nav a:hover,
nav a.active {
  color: var(--primary-color);
  border-bottom-color: var(--primary-color);
}

main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 1rem;
  min-height: calc(100vh - 300px);
}

.hero {
  text-align: center;
  padding: 3rem 1rem;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border-radius: 8px;
  margin-bottom: 2rem;
}

.hero h1 {
  font-size: 2rem;
  margin-bottom: 1rem;
  line-height: 1.3;
}

.hero .subtitle {
  font-size: 1.1rem;
  opacity: 0.95;
}

section {
  background: var(--card-bg);
  padding: 2rem;
  margin-bottom: 2rem;
  border-radius: 8px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

section h2 {
  font-size: 1.5rem;
  margin-bottom: 1.5rem;
  color: var(--primary-color);
  border-bottom: 2px solid var(--primary-color);
  padding-bottom: 0.5rem;
}

section h3 {
  font-size: 1.2rem;
  margin: 1.5rem 0 1rem;
  color: var(--text-color);
}

.intro p {
  font-size: 1rem;
  line-height: 1.8;
  color: #555;
}

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

.video-card {
  background: #fafafa;
  padding: 1.5rem;
  border-radius: 6px;
  border: 1px solid var(--border-color);
  transition: transform 0.3s, box-shadow 0.3s;
}

.video-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.video-card h3 {
  font-size: 1.1rem;
  margin: 0 0 0.5rem;
}

.video-card .year {
  font-size: 0.85rem;
  color: #777;
  margin-bottom: 0.5rem;
}

.video-card .desc {
  font-size: 0.9rem;
  color: #555;
  line-height: 1.6;
}

.video-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.video-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem;
  background: #fafafa;
  border-radius: 4px;
  border-left: 3px solid var(--primary-color);
}

.video-item a {
  flex: 1;
  font-weight: 500;
}

.video-item .meta {
  font-size: 0.85rem;
  color: #777;
  margin-left: 1rem;
}

.more-link {
  text-align: center;
  margin-top: 1.5rem;
  font-size: 1rem;
}

.more-link a {
  font-weight: 500;
  padding: 0.5rem 1rem;
  border: 2px solid var(--primary-color);
  border-radius: 4px;
  display: inline-block;
}

.more-link a:hover {
  background: var(--primary-color);
  color: white;
}

.list-page h1 {
  font-size: 2rem;
  margin-bottom: 1rem;
  color: var(--primary-color);
}

.page-desc {
  font-size: 1rem;
  color: #666;
  margin-bottom: 2rem;
  line-height: 1.8;
}

.list-container {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.list-item {
  display: flex;
  gap: 1rem;
  padding: 1.5rem;
  background: #fafafa;
  border-radius: 6px;
  border: 1px solid var(--border-color);
  transition: box-shadow 0.3s;
}

.list-item:hover {
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.list-item .rank {
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--primary-color);
  min-width: 40px;
  text-align: center;
}

.list-item .date {
  font-size: 0.9rem;
  color: #777;
  min-width: 60px;
}

.item-content {
  flex: 1;
}

.item-content h3 {
  margin: 0 0 0.5rem;
  font-size: 1.2rem;
}

.item-content .meta {
  font-size: 0.85rem;
  color: #777;
  margin-bottom: 0.5rem;
}

.item-content .desc {
  font-size: 0.95rem;
  color: #555;
  line-height: 1.6;
}

.video-detail h1 {
  font-size: 2.2rem;
  margin-bottom: 2rem;
  color: var(--primary-color);
  text-align: center;
}

.basic-info h2 {
  font-size: 1.3rem;
  margin-bottom: 1rem;
  color: var(--text-color);
}

.basic-info dl {
  display: grid;
  grid-template-columns: 100px 1fr;
  gap: 0.8rem;
  line-height: 1.8;
}

.basic-info dt {
  font-weight: 600;
  color: #555;
}

.basic-info dd {
  color: #333;
}

.highlight {
  background: #fff8f0;
  padding: 1.5rem;
  border-left: 4px solid var(--primary-color);
  border-radius: 4px;
}

.highlight p {
  font-size: 1.1rem;
  line-height: 1.8;
  color: #555;
}

.summary p,
.review p {
  font-size: 1rem;
  line-height: 1.9;
  color: #444;
  text-indent: 2em;
}

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

.related-item {
  padding: 1rem;
  background: #fafafa;
  border-radius: 4px;
  border: 1px solid var(--border-color);
}

.related-item h4 {
  margin-bottom: 0.5rem;
  font-size: 1rem;
}

.related-item p {
  font-size: 0.9rem;
  color: #666;
  line-height: 1.6;
}

footer {
  background: var(--text-color);
  color: white;
  text-align: center;
  padding: 2rem 1rem;
  margin-top: 3rem;
}

footer p {
  font-size: 0.9rem;
}

@media (max-width: 768px) {
  nav {
    padding: 0 0.5rem 0.8rem;
  }

  nav a {
    font-size: 0.8rem;
    padding: 0.4rem 0.2rem;
  }

  .logo a {
    font-size: 1.5rem;
  }

  .hero h1 {
    font-size: 1.5rem;
  }

  .hero .subtitle {
    font-size: 0.95rem;
  }

  section {
    padding: 1.5rem 1rem;
  }

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

  .basic-info dl {
    grid-template-columns: 80px 1fr;
    gap: 0.6rem;
  }

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

  .list-item {
    flex-direction: column;
    gap: 0.5rem;
  }

  .list-item .rank,
  .list-item .date {
    min-width: auto;
    text-align: left;
  }
}