.main-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px 15px;
}

.hero {
  background: #fff;
  padding: 40px 30px;
  margin-bottom: 40px;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.hero h1 {
  font-size: 28px;
  margin: 0 0 20px 0;
  color: #222;
}

.intro {
  font-size: 15px;
  line-height: 1.8;
  color: #555;
}

.intro p {
  margin: 0 0 15px 0;
}

.section {
  margin-bottom: 50px;
}

.section h2 {
  font-size: 24px;
  margin: 0 0 20px 0;
  padding-bottom: 10px;
  border-bottom: 2px solid #007bff;
}

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

.video-card {
  background: #fff;
  padding: 20px;
  border-radius: 6px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.08);
  transition: transform 0.2s, box-shadow 0.2s;
  position: relative;
}

.video-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.video-card h3 {
  font-size: 18px;
  margin: 0 0 10px 0;
}

.video-card .meta {
  font-size: 13px;
  color: #888;
  margin: 0 0 10px 0;
}

.video-card .oneline {
  font-size: 14px;
  color: #666;
  line-height: 1.6;
  margin: 0;
}

.video-card .tags {
  font-size: 12px;
  color: #999;
  margin: 10px 0 0 0;
}

.video-card.top .rank {
  position: absolute;
  top: 10px;
  right: 10px;
  background: #ff6b6b;
  color: #fff;
  width: 30px;
  height: 30px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  font-size: 14px;
}

.video-card.topic .topic-tag {
  display: inline-block;
  background: #4CAF50;
  color: #fff;
  padding: 3px 10px;
  border-radius: 3px;
  font-size: 12px;
  margin-bottom: 8px;
}

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

.link-card {
  background: #fff;
  padding: 30px 20px;
  border-radius: 6px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.08);
  text-align: center;
  transition: transform 0.2s, box-shadow 0.2s;
}

.link-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
  text-decoration: none;
}

.link-card h3 {
  font-size: 20px;
  margin: 0 0 10px 0;
  color: #007bff;
}

.link-card p {
  font-size: 14px;
  color: #666;
  margin: 0;
}

.detail {
  background: #fff;
  padding: 40px 30px;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.detail h1 {
  font-size: 32px;
  margin: 0 0 30px 0;
  color: #222;
}

.detail h2 {
  font-size: 22px;
  margin: 30px 0 15px 0;
  padding-bottom: 8px;
  border-bottom: 2px solid #007bff;
}

.info {
  background: #f9f9f9;
  padding: 20px;
  border-radius: 6px;
  margin-bottom: 30px;
}

.info-row {
  padding: 8px 0;
  border-bottom: 1px solid #eee;
  font-size: 15px;
}

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

.highlight p, .summary p, .review p {
  font-size: 16px;
  line-height: 1.8;
  color: #444;
  margin: 0 0 15px 0;
}

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

.related-card {
  background: #f9f9f9;
  padding: 15px;
  border-radius: 6px;
  transition: background 0.2s;
}

.related-card:hover {
  background: #f0f0f0;
}

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

.related-card .oneline {
  font-size: 13px;
  color: #666;
  margin: 0;
}

@media (max-width: 767px) {
  .hero {
    padding: 25px 20px;
  }

  .hero h1 {
    font-size: 22px;
  }

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

  .detail {
    padding: 25px 20px;
  }

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

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