.chapter-nav { max-width: 1200px; margin: 2rem auto; padding: 0 1rem; } .nav-controls { display: flex; gap: 1rem; margin-bottom: 2rem; } .chapter-select { flex: 1; max-width: 300px; padding: 0.5rem; border: 1px solid #ccc; border-radius: 4px; } .show-all-btn { padding: 0.5rem 1rem; background: #f3f4f6; border: 1px solid #ccc; border-radius: 4px; cursor: pointer; } .show-all-btn:hover { background: #e5e7eb; } .chapter-container { max-width: 1200px; margin: 0 auto; padding: 0 1rem; } .chapter { background: white; padding: 1.5rem; margin-bottom: 2rem; border: 1px solid #e5e7eb; border-radius: 8px; box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1); } .chapter h2 { font-size: 1.5rem; margin-bottom: 1rem; color: #1f2937; } .chapter p { line-height: 1.6; ...