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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.6;
  color: #1e272e;
  background: #f1f2f6;
}

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

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

.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 20px;
  max-width: 1200px;
  margin: 0 auto;
}

.logo {
  font-size: 24px;
  font-weight: 700;
  color: #0984e3;
  text-decoration: none;
  white-space: nowrap;
}

nav ul {
  display: flex;
  list-style: none;
  gap: 8px;
  flex-wrap: nowrap;
}

nav a {
  color: #1e272e;
  text-decoration: none;
  padding: 8px 12px;
  border-radius: 4px;
  transition: all 0.3s;
  white-space: nowrap;
  font-size: 15px;
}

nav a:hover {
  background: #0984e3;
  color: #fff;
}

main {
  padding: 32px 0;
}

h1 {
  font-size: 32px;
  margin-bottom: 24px;
  color: #1e272e;
  line-height: 1.3;
}

h2 {
  font-size: 26px;
  margin: 32px 0 20px;
  color: #1e272e;
  line-height: 1.2;
}

h3 {
  font-size: 20px;
  margin: 24px 0 16px;
  color: #1e272e;
}

section {
  background: #fff;
  border-radius: 8px;
  padding: 24px;
  margin-bottom: 32px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}

.video-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
  margin-top: 20px;
}

.video-card {
  background: #fff;
  border: 1px solid #e1e8ed;
  border-radius: 8px;
  padding: 20px;
  transition: all 0.3s;
  cursor: pointer;
}

.video-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 16px rgba(0,0,0,0.1);
  border-color: #0984e3;
}

.video-card h3 {
  margin: 0 0 12px 0;
  font-size: 18px;
}

.video-card h3 a {
  color: #1e272e;
  text-decoration: none;
}

.video-card h3 a:hover {
  color: #0984e3;
}

.video-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 12px 0;
  font-size: 13px;
  color: #666;
}

.video-meta span {
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.video-desc {
  color: #555;
  font-size: 14px;
  line-height: 1.6;
  margin-top: 12px;
}

.video-detail {
  background: #fff;
  border-radius: 8px;
  padding: 32px;
}

.video-info {
  margin: 24px 0;
  padding: 20px;
  background: #f1f2f6;
  border-radius: 6px;
}

.info-row {
  display: flex;
  margin: 12px 0;
  line-height: 1.8;
}

.info-label {
  font-weight: 600;
  min-width: 100px;
  color: #1e272e;
}

.info-value {
  color: #555;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag {
  display: inline-block;
  padding: 4px 12px;
  background: #0984e3;
  color: #fff;
  border-radius: 16px;
  font-size: 13px;
}

.summary-block, .review-block {
  margin: 24px 0;
}

.summary-block p, .review-block p {
  color: #555;
  line-height: 1.8;
  margin: 12px 0;
}

.related-section {
  margin-top: 40px;
}

.related-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 20px;
  margin-top: 20px;
}

.related-item {
  padding: 16px;
  border: 1px solid #e1e8ed;
  border-radius: 6px;
  transition: all 0.3s;
}

.related-item:hover {
  border-color: #0984e3;
  background: #f1f2f6;
}

.related-item h4 {
  margin: 0 0 8px 0;
  font-size: 16px;
}

.related-item h4 a {
  color: #1e272e;
  text-decoration: none;
}

.related-item p {
  font-size: 13px;
  color: #666;
  line-height: 1.5;
}

footer {
  background: #1e272e;
  color: #fff;
  text-align: center;
  padding: 24px 20px;
  margin-top: 48px;
}

footer a {
  color: #fff;
  text-decoration: none;
}

@media (max-width: 768px) {
  .header-inner {
    flex-direction: column;
    gap: 12px;
    padding: 12px 16px;
  }

  nav ul {
    width: 100%;
    justify-content: space-between;
    gap: 4px;
  }

  nav a {
    padding: 6px 8px;
    font-size: 13px;
    flex: 1 1 0;
    min-width: 0;
    text-align: center;
    overflow: hidden;
    text-overflow: ellipsis;
  }

  .logo {
    font-size: 20px;
  }

  h1 {
    font-size: 24px;
  }

  h2 {
    font-size: 20px;
  }

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

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

  section {
    padding: 16px;
  }

  .video-detail {
    padding: 20px;
  }
}