/* toc.css — collapsible table of contents */
.toc { padding-block: 1.25rem; }
.toc__box {
  background: var(--color-bg-dark);
  border: 1px solid var(--color-cool-blue);
  clip-path: var(--clip-cut);
  padding: 0.5rem;
}
.toc__toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 0.85rem 1rem;
  color: var(--color-white);
  font-weight: var(--fw-btn);
  font-size: 1.05rem;
}
.toc__title { color: var(--color-heading); }
.toc__arrow { transition: transform var(--transition-fast); color: var(--color-accent-bg); }
.toc__toggle[aria-expanded="true"] .toc__arrow { transform: rotate(180deg); }

.toc__list {
  display: grid;
  gap: 0.15rem;
  padding: 0 0.5rem;
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition), padding var(--transition);
}
.toc__list.is-open { max-height: 1200px; padding: 0.5rem; }
.toc__list li { display: block; }
.toc__list a {
  display: block;
  padding: 0.6rem 0.75rem;
  color: var(--color-text);
  border-bottom: 1px solid rgba(57, 73, 80, 0.35);
  transition: color var(--transition-fast), padding-left var(--transition-fast);
}
.toc__list li:last-child a { border-bottom: none; }
.toc__list a:hover, .toc__list a:focus-visible { color: var(--color-heading); padding-left: 1.1rem; }

/* On desktop (>=768px) TOC is expanded by default */
@media (min-width: 768px) {
  .toc__list { max-height: 1600px; padding: 0.5rem; }
}