/* toc.css */
.toc {
  background: var(--c-card);
  border-radius: var(--radius);
  padding: 0.5rem;
  margin-block: var(--sp-paragraph);
}
.toc__toggle {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem 1rem;
  color: var(--c-heading);
  font-weight: var(--fw-bold);
  font-size: 1.1rem;
  border-radius: var(--radius);
}
.toc__arrow { transition: transform var(--transition); flex: 0 0 auto; }
.toc__toggle[aria-expanded="false"] .toc__arrow { transform: rotate(-90deg); }

/* Collapsible panel via grid-template-rows animation */
.toc__panel {
  display: grid;
  grid-template-rows: 1fr;
  transition: grid-template-rows var(--transition);
}
.toc.is-collapsed .toc__panel { grid-template-rows: 0fr; }
.toc__list {
  overflow: hidden;
  min-height: 0;
  padding-inline: 1rem;
}
.toc:not(.is-collapsed) .toc__list { padding-bottom: 0.75rem; }

.toc__item { border-top: 1px solid var(--c-border-soft); }
.toc__link {
  display: block;
  padding: 0.65rem 0.25rem;
  color: var(--c-text);
  transition: color var(--transition-fast), padding-left var(--transition-fast);
}
.toc__link:hover { color: var(--c-heading); padding-left: 0.5rem; }

@media (prefers-reduced-motion: reduce) {
  .toc__panel, .toc__arrow { transition: none; }
}