/* =========================================================
   Table of Contents (TOC)
   ========================================================= */
.toc-container {
  margin: 1.75rem 0 2.25rem;
  background: var(--panel);
  border: 1px solid var(--border-subtle);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-sm);
}

.toc-header {
  all: unset;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;

  padding: 0.9rem 1.25rem;
  cursor: pointer;

  font-size: 0.8rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  /* removes the 300ms delay and improves tap reliability */
  touch-action: manipulation;
}

/* Rotate when open */
.toc-container.is-open .toc-header-icon {
  transform: rotate(90deg);
}

/* TOC list */
ul.toc {
  list-style: none;
  padding: 0 1.35rem 1.1rem;
  font-size: 0.95rem;
  margin: 0;
}

/* Individual TOC items */
ul.toc li {
  margin: 0.35rem 0;
}

/* TOC links */
ul.toc a {
  color: var(--text);
  text-decoration: none;
  transition:
    color var(--hover-duration) var(--hover-ease),
    text-shadow var(--hover-duration) var(--hover-ease);
}

/* Hover / focus state */
ul.toc a:hover,
ul.toc a:focus {
  color: var(--accent-warm);
  text-shadow: 0 0 6px var(--accent-glow);
}

ul.toc a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 2px;
}

/* Optional: subtle marker */
ul.toc li::marker {
  color: var(--accent);
}

/* Make TOC visually quieter than main content */
ul.toc a {
  font-weight: 500;
}

/* =========================================================
   Nested TOC (H3+)
   ========================================================= */

ul.toc ul {
  margin-top: 0.35rem;
  padding-left: 1.1rem;
  border-left: 1px dashed var(--border-soft);
}

ul.toc ul li {
  font-size: 0.92rem;
}

ul.toc ul ul li {
  font-size: 0.88rem;
  color: var(--text-muted);
}

/* Hide toggles for deepest level */
ul.toc ul ul .toc-toggle {
  display: none;
}


/* =========================================================
   TOC Collapsible Nested Levels
   ========================================================= */

/* Hide nested lists by default */
ul.toc li > ul {
  margin-top: 0.4rem;
  transition: opacity var(--hover-duration) var(--hover-ease);
}

/* Show when expanded */
ul.toc li.is-expanded > ul {
  display: block;
}

ul.toc li:not(.is-expanded) > ul {
  opacity: 0;
}

/* Make parent items clickable containers */
ul.toc li {
  position: relative;
}

/* Toggle button */
ul.toc .toc-toggle {
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
  margin-left: 0.5rem;

  font-size: 0.7rem;
  color: var(--text-muted);
  transition: color var(--hover-duration) var(--hover-ease),
              transform var(--hover-duration) var(--hover-ease);
}

/* Toggle button reset */
.toc-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;

  background: none;
  border: none;
  padding: 0;
  cursor: pointer;

  color: var(--text-muted);
  transition:
    color var(--hover-duration) var(--hover-ease),
    transform var(--hover-duration) var(--hover-ease);
}

.toc-icon {
  width: 0.85rem;
  height: 0.85rem;
}

/* Hover */
ul.toc .toc-toggle:hover {
  color: var(--accent);
}

/* Rotate indicator when open */
ul.toc li.is-expanded > .toc-toggle {
  transform: rotate(90deg);
}

/* =========================================================
   TOC Expand / Collapse Animation
   ========================================================= */

ul.toc li > ul {
  display: none;
  grid-template-rows: 0fr;
  overflow: hidden;

  opacity: 0;
  transform: translateY(-2px);

  transition:
    grid-template-rows var(--motion-fast) var(--motion-ease),
    opacity var(--hover-duration) var(--hover-ease),
    transform var(--hover-duration) var(--hover-ease);
  transition-delay: 0ms;
}

/* Expanded state */
ul.toc li.is-expanded > ul {
  display: grid;
  grid-template-rows: 1fr;
  opacity: 1;
  transform: translateY(0);
  transition-delay: 40ms;
}

/* Inner list wrapper */
ul.toc li > ul > li {
  min-height: 0;
}

/* Desktop media query */
@media (min-width: 769px) {
  .toc-container {
    max-width: 42rem;
  }

  .toc-header {
    cursor: default;
  }
}

/* Mobile media query */
@media (max-width: 768px) {
  .toc-container ul.toc {
    display: none;
  }

  .toc-container.is-open ul.toc {
    display: block;
  }
}

/* Motion */
@media (prefers-reduced-motion: reduce) {
  ul.toc li > ul {
    transition: none;
  }
}