/**
 * Subject index pages — chapter list pattern
 */

.subject-page .app-main {
  padding-top: var(--space-8);
  padding-bottom: var(--space-16);
}

.subject-breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-6);
}

.subject-breadcrumb a {
  color: var(--color-text-secondary);
  text-decoration: none;
}

.subject-breadcrumb a:hover {
  color: var(--color-brand-600);
}

.subject-hero {
  margin-bottom: var(--space-10);
  padding-bottom: var(--space-8);
  border-bottom: 1px solid var(--color-border);
}

.subject-hero__accent {
  display: inline-block;
  width: 3rem;
  height: 4px;
  border-radius: var(--radius-full);
  background: var(--subject-accent, var(--color-brand-600));
  margin-bottom: var(--space-4);
}

.subject-hero--ancient { --subject-accent: #b45309; }
.subject-hero--medieval { --subject-accent: #4f46e5; }
.subject-hero--modern { --subject-accent: #dc2626; }
.subject-hero--art { --subject-accent: #db2777; }
.subject-hero--economics { --subject-accent: #059669; }

.subject-hero__title {
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: var(--font-bold);
  letter-spacing: -0.03em;
  margin: 0 0 var(--space-3);
  color: var(--color-text);
}

.subject-hero__desc {
  font-size: var(--text-base);
  color: var(--color-text-secondary);
  margin: 0 0 var(--space-4);
  max-width: 36rem;
  line-height: var(--leading-relaxed);
}

.subject-hero__meta {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin: 0;
}

.chapter-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.chapter-row {
  margin: 0;
}

.chapter-row__link {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-4) var(--space-5);
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  text-decoration: none;
  color: inherit;
  transition: border-color var(--transition-fast), background var(--transition-fast), box-shadow var(--transition-fast), transform var(--transition-fast);
}

.chapter-row__link:hover {
  border-color: var(--color-brand-500);
  background: var(--color-bg-subtle);
  box-shadow: var(--shadow-sm);
  transform: translateX(4px);
  text-decoration: none;
  color: inherit;
}

.chapter-row__num {
  flex-shrink: 0;
  width: 1.5rem;
  font-size: var(--text-sm);
  font-weight: var(--font-bold);
  color: var(--color-text-muted);
  font-variant-numeric: tabular-nums;
}

.chapter-row__symbol {
  flex-shrink: 0;
  width: 2.75rem;
  height: 2.75rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.35rem;
  line-height: 1;
  background: var(--color-bg-muted);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.chapter-row__link:hover .chapter-row__symbol {
  transform: scale(1.08);
  box-shadow: var(--shadow-sm);
}

.subject-hero__symbol {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 3.5rem;
  height: 3.5rem;
  font-size: 1.75rem;
  background: var(--color-bg-muted);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  margin-bottom: var(--space-4);
  box-shadow: var(--shadow-xs);
}

.chapter-row__body {
  flex: 1;
  min-width: 0;
}

.chapter-row__title {
  font-size: var(--text-base);
  font-weight: var(--font-semibold);
  color: var(--color-text);
  margin: 0;
}

.chapter-row__sub {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  margin: var(--space-1) 0 0;
}

.chapter-row__arrow {
  flex-shrink: 0;
  color: var(--color-text-muted);
  font-size: var(--text-lg);
  transition: transform var(--transition-fast);
}

.chapter-row__link:hover .chapter-row__arrow {
  transform: translateX(4px);
  color: var(--color-brand-600);
}