/* Phase 4: Class/Chapter pages */
.up-hero-class { padding: 60px 20px; text-align: center; background: var(--color-primary); color: #fff; border-radius: 0 0 24px 24px; }
.up-hero-class h1 { font-size: 40px; margin-top: 12px; }
.up-breadcrumb a { color: inherit; opacity: 0.85; text-decoration: none; }
.up-chapter-grid { display: flex; flex-wrap: wrap; gap: 24px; padding: 60px 20px; max-width: 1200px; margin: 0 auto; justify-content: center; }
.up-chapter-card, .up-content-card, .up-pdf-card { background: var(--color-card); border-radius: 16px; padding: 24px; width: 280px; box-shadow: 0 4px 12px rgba(0,0,0,0.06); transition: transform .3s, box-shadow .3s; position: relative; }
.up-chapter-card:hover, .up-content-card:hover, .up-pdf-card:hover { transform: translateY(-6px); box-shadow: 0 12px 24px rgba(0,0,0,0.1); }
.up-chapter-number { position: absolute; top: 12px; left: 12px; background: var(--color-accent); color: #fff; border-radius: 50%; width: 32px; height: 32px; display: flex; align-items: center; justify-content: center; font-weight: bold; }
.up-chapter-card img, .up-content-card img, .up-pdf-card img { width: 100%; border-radius: 10px; margin-bottom: 12px; }
.up-chapter-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.up-btn, .up-btn-primary, .up-btn-outline { display: inline-block; padding: 10px 20px; border-radius: 8px; text-decoration: none; font-size: 14px; cursor: pointer; border: none; }
.up-btn-primary { background: var(--color-primary); color: #fff; }
.up-btn-outline { background: transparent; border: 1.5px solid var(--color-primary); color: var(--color-primary); }
.up-btn-icon { background: var(--color-background); border-radius: 50%; width: 36px; height: 36px; border: none; cursor: pointer; }
.up-single-chapter { max-width: 900px; margin: 0 auto; padding: 40px 20px; }
.up-chapter-content { font-size: 19px; line-height: 2.1; margin: 30px 0; }
.up-chapter-block, .up-chapter-video, .up-chapter-pdf { background: var(--color-card); padding: 24px; border-radius: 12px; margin-bottom: 24px; }
.up-chapter-nav { display: flex; justify-content: space-between; margin: 40px 0; flex-wrap: wrap; gap: 12px; }
.up-related-chapters { margin-top: 40px; }
.up-empty { text-align: center; padding: 40px; color: #64748B; }
@media (max-width: 768px) {
    .up-hero-class h1 { font-size: 28px; }
    .up-chapter-nav { flex-direction: column; }
}