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

main { min-height: calc(100vh - 200px); padding: 2rem 0; }

.hero { background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); color: #fff; padding: 3rem 0; text-align: center; }
.hero h1 { font-size: 2rem; margin-bottom: 1rem; }
.hero .subtitle { font-size: 1rem; opacity: 0.9; }

.intro { background: #fff; padding: 2rem 0; margin: 2rem 0; border-radius: 8px; box-shadow: 0 2px 8px rgba(0,0,0,0.05); }
.intro p { font-size: 1rem; line-height: 1.8; }

section { margin: 2rem 0; }
section h2 { font-size: 1.8rem; margin-bottom: 1.5rem; color: #2c3e50; border-left: 4px solid #667eea; padding-left: 1rem; }

.video-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 1.5rem; margin: 2rem 0; }
.video-card { background: #fff; padding: 1.5rem; border-radius: 8px; box-shadow: 0 2px 8px rgba(0,0,0,0.08); transition: all 0.3s; }
.video-card:hover { transform: translateY(-4px); box-shadow: 0 4px 16px rgba(0,0,0,0.12); }
.video-card h3 { font-size: 1.2rem; margin-bottom: 0.8rem; }
.video-card h3 a { color: #2c3e50; text-decoration: none; }
.video-card h3 a:hover { color: #667eea; }
.video-card .meta { font-size: 0.9rem; color: #7f8c8d; margin-bottom: 0.5rem; }
.video-card .desc { font-size: 0.95rem; color: #555; line-height: 1.6; }

.more-link { text-align: center; margin-top: 2rem; font-size: 1rem; }
.more-link a { color: #667eea; text-decoration: none; padding: 0.5rem 1rem; border: 1px solid #667eea; border-radius: 4px; transition: all 0.3s; display: inline-block; margin: 0 0.5rem; }
.more-link a:hover { background: #667eea; color: #fff; }

.topic-entry { background: #fff; padding: 2rem; border-radius: 8px; box-shadow: 0 2px 8px rgba(0,0,0,0.05); }

.list-header { background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); color: #fff; padding: 2rem 0; margin-bottom: 2rem; }
.list-header h1 { font-size: 2rem; margin-bottom: 1rem; }

.video-list { background: #fff; padding: 2rem; border-radius: 8px; }
.video-item { padding: 1.5rem 0; border-bottom: 1px solid #ecf0f1; position: relative; }
.video-item:last-child { border-bottom: none; }
.video-item h3, .video-item h4 { font-size: 1.3rem; margin-bottom: 0.5rem; }
.video-item h3 a, .video-item h4 a { color: #2c3e50; text-decoration: none; }
.video-item h3 a:hover, .video-item h4 a:hover { color: #667eea; }
.video-item .meta { font-size: 0.9rem; color: #7f8c8d; margin-bottom: 0.5rem; }
.video-item .summary { font-size: 1rem; color: #555; line-height: 1.7; }

.video-item.ranked { padding-left: 4rem; }
.rank-badge { position: absolute; left: 0; top: 50%; transform: translateY(-50%); width: 3rem; height: 3rem; background: #667eea; color: #fff; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 1.5rem; font-weight: bold; }

.topic-group { margin: 2rem 0; }
.group-title { font-size: 1.4rem; color: #667eea; margin-bottom: 1rem; padding-bottom: 0.5rem; border-bottom: 2px solid #667eea; }

.detail-page { background: #fff; padding: 2rem; border-radius: 8px; }
.detail-header { text-align: center; padding: 2rem 0; border-bottom: 2px solid #ecf0f1; }
.detail-header h1 { font-size: 2.5rem; margin-bottom: 0.5rem; color: #2c3e50; }
.detail-header .subtitle { font-size: 1rem; color: #7f8c8d; }

.detail-info, .detail-oneline, .detail-summary, .detail-review, .detail-related { margin: 2rem 0; }
.detail-info h2, .detail-oneline h2, .detail-summary h2, .detail-review h2, .detail-related h2 { font-size: 1.6rem; margin-bottom: 1rem; color: #2c3e50; border-left: 4px solid #667eea; padding-left: 1rem; }

.info-list { list-style: none; }
.info-list li { padding: 0.5rem 0; font-size: 1rem; line-height: 1.6; }

.highlight { font-size: 1.1rem; color: #667eea; font-weight: 500; line-height: 1.8; }

.detail-summary p, .detail-review p { font-size: 1rem; line-height: 1.8; color: #444; text-align: justify; }

.related-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 1.5rem; }
.related-card { background: #f8f9fa; padding: 1.5rem; border-radius: 6px; border: 1px solid #e9ecef; }
.related-card h3 { font-size: 1.1rem; margin-bottom: 0.5rem; }
.related-card h3 a { color: #2c3e50; text-decoration: none; }
.related-card h3 a:hover { color: #667eea; }
.related-card .meta { font-size: 0.85rem; color: #7f8c8d; margin-bottom: 0.5rem; }
.related-card .desc { font-size: 0.9rem; color: #555; line-height: 1.5; }

footer { background: #2c3e50; color: #ecf0f1; text-align: center; padding: 2rem 0; margin-top: 3rem; }
footer p { font-size: 0.9rem; }

@media (max-width: 768px) {
  .hero h1 { font-size: 1.5rem; }
  .detail-header h1 { font-size: 1.8rem; }
  .video-grid, .related-grid { grid-template-columns: 1fr; }
  section h2 { font-size: 1.5rem; }
}