/* toc.css (BEM) — collapsible quick navigation */
.toc {
  background: var(--color-card);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-soft);
  overflow: hidden;
  margin-block: var(--space-section);
}
.toc__toggle {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: var(--card-padding);
  color: var(--color-white);
  font-weight: var(--fw-bold);
  font-size: var(--fs-h3);
  text-align: left;
}
.toc__arrow {
  width: 12px; height: 12px;
  border-right: 3px solid var(--color-heading);
  border-bottom: 3px solid var(--color-heading);
  transform: rotate(45deg);
  transition: transform var(--transition);
  flex: 0 0 auto;
}
.toc__toggle[aria-expanded="false"] .toc__arrow { transform: rotate(-45deg); }
.toc__list {
  display: grid;
  gap: 0.25rem;
  padding: 0 var(--card-padding) var(--card-padding);
}
.toc__list[hidden] { display: none; }
.toc__item a {
  display: block;
  padding: 0.6rem 0.5rem;
  color: var(--color-text);
  border-radius: var(--radius-sm);
  border-left: 3px solid transparent;
  transition: color var(--transition-fast), border-color var(--transition-fast), background var(--transition-fast);
}
.toc__item a:hover {
  color: var(--color-heading);
  border-left-color: var(--color-heading);
  background: rgba(155, 232, 106, 0.06);
}
.toc__item--active a { color: var(--color-heading); border-left-color: var(--color-heading); }