.chapter-header {
  margin-bottom: var(--space-5);
  padding: var(--space-5);
  border-radius: var(--radius-lg);
  border-top: 8px solid var(--strand-color);
  background: var(--color-surface);
  box-shadow: var(--shadow-soft);
}

.chapter-header__label {
  display: flex;
  align-items: center;
  color: var(--color-text-muted);
  font-weight: 700;
}

.chapter-header__meta {
  margin: 0;
  color: var(--color-text-muted);
}

.lesson-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: var(--space-4);
  margin: 0;
  padding: 0;
  list-style: none;
}

.lesson-card {
  display: grid;
  grid-template-columns: auto 1fr;
  grid-template-areas:
    'type number'
    'title title'
    'meta meta';
  align-items: center;
  gap: var(--space-2) var(--space-3);
  height: 100%;
  padding: var(--space-4);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  color: var(--color-text);
  text-decoration: none;
}

.lesson-card--open {
  border-color: var(--strand-color);
  box-shadow: var(--shadow-soft);
  transition: transform var(--duration-base) var(--ease-pop);
}

.lesson-card--open:hover {
  transform: translateY(-4px);
}

.lesson-card--locked {
  background: var(--color-surface-muted);
}

.lesson-card--locked .lesson-card__title {
  color: var(--color-text-muted);
}

.lesson-card__type {
  grid-area: type;
  font-size: var(--font-size-xl);
  line-height: 1;
}

.lesson-card__number {
  grid-area: number;
  font-family: var(--font-heading);
  font-weight: 800;
  color: var(--color-text-muted);
}

.lesson-card__title {
  grid-area: title;
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.35;
}

.lesson-card__meta {
  grid-area: meta;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  color: var(--color-text-muted);
  font-size: var(--font-size-sm);
}