body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: #2c3e50;
  line-height: 1.8;
}

header {
  background: rgba(255, 255, 255, 0.98);
  padding: 20px 0;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

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

.logo {
  font-size: 32px;
  font-weight: 700;
  color: #2c3e50;
  text-align: center;
}

.logo a {
  color: #e74c3c;
  text-decoration: none;
  transition: color 0.3s;
}

.logo a:hover {
  color: #c0392b;
}

.main-nav {
  background: #fff;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-container {
  display: flex;
  flex-wrap: nowrap;
  justify-content: space-between;
  align-items: center;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0;
}

.main-nav a {
  flex: 1 1 0;
  min-width: 0;
  text-align: center;
  padding: 16px 12px;
  text-decoration: none;
  color: #34495e;
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  transition: all 0.3s ease;
  border-bottom: 3px solid transparent;
  font-size: 16px;
}

.main-nav a:hover,
.main-nav a.active {
  color: #e74c3c;
  border-bottom-color: #e74c3c;
  background: rgba(231, 76, 60, 0.05);
}

@media (max-width: 768px) {
  .main-nav a {
    padding: 12px 6px;
    font-size: 13px;
  }
}

@media (max-width: 480px) {
  .main-nav a {
    padding: 10px 4px;
    font-size: 12px;
  }
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 20px;
  background: #fff;
  min-height: calc(100vh - 200px);
}

.hero {
  text-align: center;
  padding: 60px 20px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: #fff;
  border-radius: 12px;
  margin-bottom: 40px;
  box-shadow: 0 10px 40px rgba(0,0,0,0.2);
}

.hero h1 {
  font-size: 36px;
  line-height: 1.4;
  margin-bottom: 20px;
  font-weight: 700;
}

.intro-section {
  padding: 40px;
  background: #f8f9fa;
  border-radius: 8px;
  margin-bottom: 40px;
  font-size: 16px;
  line-height: 2;
}

.intro-section p {
  margin-bottom: 16px;
}

.content-section {
  margin-bottom: 60px;
}

.content-section h2 {
  font-size: 28px;
  color: #2c3e50;
  margin-bottom: 30px;
  padding-bottom: 15px;
  border-bottom: 3px solid #e74c3c;
}

.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
  margin-bottom: 30px;
}

.video-card {
  background: #fff;
  border: 1px solid #e0e0e0;
  border-radius: 8px;
  padding: 20px;
  transition: all 0.3s ease;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}

.video-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 20px rgba(0,0,0,0.15);
  border-color: #e74c3c;
}

.video-card h3 {
  font-size: 18px;
  margin-bottom: 12px;
  color: #2c3e50;
}

.video-card h3 a {
  color: #2c3e50;
  text-decoration: none;
  transition: color 0.3s;
}

.video-card h3 a:hover {
  color: #e74c3c;
}

.meta {
  font-size: 14px;
  color: #7f8c8d;
  margin-bottom: 12px;
}

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

.more-link {
  text-align: center;
  margin-top: 30px;
}

.more-link a {
  display: inline-block;
  margin: 0 15px;
  padding: 12px 30px;
  background: #e74c3c;
  color: #fff;
  text-decoration: none;
  border-radius: 25px;
  font-weight: 500;
  transition: all 0.3s ease;
}

.more-link a:hover {
  background: #c0392b;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(231,76,60,0.4);
}

.page-title {
  font-size: 32px;
  color: #2c3e50;
  margin-bottom: 30px;
  padding-bottom: 20px;
  border-bottom: 3px solid #e74c3c;
}

.page-intro {
  background: #f8f9fa;
  padding: 30px;
  border-radius: 8px;
  margin-bottom: 40px;
  font-size: 16px;
  line-height: 2;
}

.list-container {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.list-item {
  background: #fff;
  border: 1px solid #e0e0e0;
  border-radius: 8px;
  padding: 24px;
  transition: all 0.3s ease;
}

.list-item:hover {
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
  border-color: #e74c3c;
}

.list-item h3 {
  font-size: 20px;
  margin-bottom: 12px;
}

.list-item h3 a {
  color: #2c3e50;
  text-decoration: none;
}

.list-item h3 a:hover {
  color: #e74c3c;
}

.tags {
  margin-top: 12px;
}

.tags span {
  display: inline-block;
  padding: 4px 12px;
  background: #ecf0f1;
  color: #555;
  font-size: 12px;
  border-radius: 12px;
  margin-right: 8px;
  margin-bottom: 8px;
}

.rank-container {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.rank-item {
  display: flex;
  align-items: flex-start;
  background: #fff;
  border: 1px solid #e0e0e0;
  border-radius: 8px;
  padding: 24px;
  transition: all 0.3s ease;
}

.rank-item:hover {
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
  border-color: #e74c3c;
}

.rank-number {
  flex-shrink: 0;
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: #fff;
  font-size: 24px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  margin-right: 20px;
}

.rank-content {
  flex: 1;
}

.rank-content h3 {
  font-size: 20px;
  margin-bottom: 12px;
}

.rank-content h3 a {
  color: #2c3e50;
  text-decoration: none;
}

.rank-content h3 a:hover {
  color: #e74c3c;
}

.review {
  margin-top: 12px;
  padding: 12px;
  background: #f8f9fa;
  border-left: 4px solid #e74c3c;
  font-style: italic;
  color: #555;
}

.topic-section {
  margin-bottom: 50px;
}

.topic-section h2 {
  font-size: 24px;
  color: #2c3e50;
  margin-bottom: 24px;
  padding-left: 15px;
  border-left: 5px solid #e74c3c;
}

.topic-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}

.topic-card {
  background: #fff;
  border: 1px solid #e0e0e0;
  border-radius: 8px;
  padding: 20px;
  transition: all 0.3s ease;
}

.topic-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 16px rgba(0,0,0,0.1);
  border-color: #e74c3c;
}

.topic-card h3 {
  font-size: 18px;
  margin-bottom: 10px;
}

.topic-card h3 a {
  color: #2c3e50;
  text-decoration: none;
}

.topic-card h3 a:hover {
  color: #e74c3c;
}

.latest-container {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.latest-item {
  display: flex;
  align-items: flex-start;
  background: #fff;
  border: 1px solid #e0e0e0;
  border-radius: 8px;
  padding: 24px;
  transition: all 0.3s ease;
}

.latest-item:hover {
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
  border-color: #e74c3c;
}

.latest-date {
  flex-shrink: 0;
  padding: 8px 16px;
  background: #e74c3c;
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  border-radius: 20px;
  margin-right: 20px;
}

.latest-content {
  flex: 1;
}

.latest-content h3 {
  font-size: 20px;
  margin-bottom: 12px;
}

.latest-content h3 a {
  color: #2c3e50;
  text-decoration: none;
}

.latest-content h3 a:hover {
  color: #e74c3c;
}

.detail-page {
  max-width: 900px;
  margin: 0 auto;
}

.detail-page h1 {
  font-size: 32px;
  color: #2c3e50;
  margin-bottom: 40px;
  padding-bottom: 20px;
  border-bottom: 3px solid #e74c3c;
  text-align: center;
}

.info-section,
.highlight-section,
.summary-section,
.review-section,
.related-section {
  margin-bottom: 40px;
  padding: 30px;
  background: #f8f9fa;
  border-radius: 8px;
}

.info-section h2,
.highlight-section h2,
.summary-section h2,
.review-section h2,
.related-section h2 {
  font-size: 24px;
  color: #2c3e50;
  margin-bottom: 20px;
  padding-bottom: 10px;
  border-bottom: 2px solid #e74c3c;
}

.info-list {
  list-style: none;
  padding: 0;
}

.info-list li {
  padding: 10px 0;
  border-bottom: 1px solid #e0e0e0;
  font-size: 16px;
}

.info-list li:last-child {
  border-bottom: none;
}

.tag-list {
  margin-top: 20px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.tag {
  display: inline-block;
  padding: 6px 16px;
  background: #3498db;
  color: #fff;
  font-size: 14px;
  border-radius: 20px;
  font-weight: 500;
}

.highlight {
  font-size: 18px;
  line-height: 1.8;
  color: #2c3e50;
  font-weight: 500;
  padding: 20px;
  background: #fff;
  border-left: 5px solid #e74c3c;
}

.summary-section p {
  font-size: 16px;
  line-height: 2;
  color: #34495e;
  text-indent: 2em;
}

.review-text {
  font-size: 16px;
  line-height: 2;
  color: #555;
  padding: 20px;
  background: #fff;
  border-left: 5px solid #3498db;
  font-style: italic;
}

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

.related-card {
  background: #fff;
  border: 1px solid #e0e0e0;
  border-radius: 8px;
  padding: 20px;
  transition: all 0.3s ease;
}

.related-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 16px rgba(0,0,0,0.1);
  border-color: #e74c3c;
}

.related-card h4 {
  font-size: 16px;
  margin-bottom: 10px;
}

.related-card h4 a {
  color: #2c3e50;
  text-decoration: none;
}

.related-card h4 a:hover {
  color: #e74c3c;
}

.related-card p {
  font-size: 14px;
  line-height: 1.6;
  color: #555;
}

footer {
  background: #2c3e50;
  color: #ecf0f1;
  text-align: center;
  padding: 30px 20px;
  margin-top: 60px;
}

footer p {
  margin: 0;
  font-size: 14px;
}

@media (max-width: 768px) {
  .hero h1 {
    font-size: 24px;
  }

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

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

  .rank-number {
    margin-bottom: 15px;
  }

  .latest-date {
    margin-bottom: 15px;
  }

  .detail-page h1 {
    font-size: 24px;
  }
}