frontend/src/styles/components/_toc.css

/* ============================================================================ */
/* Table of Contents                                                           */
/* Extracted from TableOfContents.astro scoped styles.                         */
/* Shared between editor and publisher.                                        */
/* ============================================================================ */

/* Loading state */
.table-of-contents.toc-loading,
.toc-mobile-sidebar.toc-loading {
  opacity: 0;
  transition: opacity 0.3s ease-in-out;
}
.table-of-contents.toc-loaded,
.toc-mobile-sidebar.toc-loaded {
  opacity: 1;
}

/* Desktop TOC */
.table-of-contents {
  position: sticky;
  top: 32px;
  margin-top: 12px;
}

.table-of-contents nav {
  border-left: 1px solid var(--border-color);
  padding-left: 16px;
  font-size: 13px;
}

.table-of-contents .title {
  font-weight: 600;
  font-size: 14px;
  margin-bottom: 8px;
}

.table-of-contents nav ul {
  margin: 0 0 6px;
  padding-left: 1em;
}

.table-of-contents nav li {
  list-style: none;
  margin: 0.25em 0;
}

.table-of-contents nav a,
.table-of-contents nav a:link,
.table-of-contents nav a:visited {
  color: var(--text-color);
  text-decoration: none;
  border-bottom: none;
  background: none;
  cursor: pointer;
}

.table-of-contents nav > ul > li > a {
  font-weight: 700;
}

.table-of-contents nav a:hover {
  text-decoration: underline solid var(--muted-color);
}

.table-of-contents nav a.active {
  color: var(--primary-color);
  text-decoration: underline;
  text-decoration-color: color-mix(in srgb, var(--primary-color) 50%, transparent);
  text-underline-offset: 2px;
}

/* Collapsible sub-sections.
   We wrap every nested <ul> in a <div class="toc-children"> and animate via
   the grid-template-rows 0fr/1fr trick (CSS can't animate height:auto).
   This matches the editor-side React implementation. */
.toc-children {
  display: grid;
  grid-template-rows: 1fr;
  opacity: 1;
  overflow: hidden;
  transition: grid-template-rows 200ms ease, opacity 200ms ease;
}
.toc-children > * {
  overflow: hidden;
  min-height: 0;
}
.toc-collapsible li.collapsed > .toc-children {
  grid-template-rows: 0fr;
  opacity: 0;
}

/* Applied on the nav root during init to suppress transitions for the first
   paint, then removed on the next animation frame. Avoids a close-animation
   flash when auto-collapse is enabled. */
.toc-collapsible.toc-no-transition .toc-children,
.toc-collapsible.toc-no-transition .toc-children > * {
  transition: none !important;
}

/* ============================================================================ */
/* Mobile TOC - toggle button                                                   */
/* Hidden on desktop, shown at @media (max-width: 1100px) below.                */
/* ============================================================================ */

.toc-mobile-toggle {
  display: none;
  position: fixed;
  top: var(--spacing-4);
  left: var(--spacing-4);
  z-index: var(--z-overlay);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--border-color);
  background: var(--page-bg);
  box-shadow: 0 2px 12px rgba(0,0,0,.08);
  align-items: center;
  justify-content: center;
  padding: 0;
  cursor: pointer;
  color: var(--text-color);
  transition: transform 150ms ease, box-shadow 150ms ease;
}
.toc-mobile-toggle:active {
  transform: scale(0.92);
}

/* ============================================================================ */
/* Mobile TOC - backdrop                                                        */
/* ============================================================================ */

.toc-mobile-backdrop {
  display: none;
  position: fixed;
  inset: 0;
  z-index: calc(var(--z-overlay) + 1);
  background: rgba(0,0,0,.4);
  opacity: 0;
  pointer-events: none;
  transition: opacity 250ms ease;
}
.toc-mobile-backdrop.open {
  opacity: 1;
  pointer-events: auto;
}

/* ============================================================================ */
/* Mobile TOC - sidebar panel                                                   */
/* ============================================================================ */

.toc-mobile-sidebar {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: calc(var(--z-overlay) + 2);
  width: min(320px, 85vw);
  background: var(--page-bg);
  border-right: 1px solid var(--border-color);
  transform: translateX(-100%);
  transition: transform 300ms cubic-bezier(.4,0,.2,1);
  flex-direction: column;
}
.toc-mobile-sidebar.open {
  transform: translateX(0);
}

.toc-mobile-sidebar__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px;
  border-bottom: 1px solid var(--border-color);
  flex-shrink: 0;
}

.toc-mobile-sidebar__title {
  font-weight: 700;
  font-size: 15px;
  color: var(--text-color);
}

.toc-mobile-sidebar__actions {
  display: flex;
  align-items: center;
  gap: 4px;
}

.toc-mobile-sidebar__close,
.toc-mobile-sidebar__theme {
  background: none;
  border: none;
  color: var(--muted-color);
  cursor: pointer;
  padding: 4px;
  border-radius: 6px;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color 150ms ease, background 150ms ease;
}
.toc-mobile-sidebar__close:hover,
.toc-mobile-sidebar__theme:hover {
  color: var(--text-color);
  background: var(--surface-bg);
}

/* Theme icon visibility in sidebar */
.toc-mobile-sidebar__theme .icon.dark {
  display: none;
}
[data-theme="dark"] .toc-mobile-sidebar__theme .icon.light {
  display: none;
}
[data-theme="dark"] .toc-mobile-sidebar__theme .icon.dark {
  display: inline;
}

.toc-mobile-sidebar__body {
  flex: 1;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  padding: 16px;
}

/* TOC styles inside mobile sidebar */
.toc-mobile-sidebar nav ul {
  margin: 0 0 6px;
  padding-left: 1em;
}
.toc-mobile-sidebar nav li {
  list-style: none;
  margin: 0.35em 0;
}
.toc-mobile-sidebar nav a,
.toc-mobile-sidebar nav a:link,
.toc-mobile-sidebar nav a:visited {
  color: var(--text-color);
  text-decoration: none;
  border-bottom: none;
  font-size: 14px;
  line-height: 1.5;
}
.toc-mobile-sidebar nav > ul > li > a {
  font-weight: 700;
}
.toc-mobile-sidebar nav a:hover {
  text-decoration: underline solid var(--muted-color);
}
.toc-mobile-sidebar nav a.active {
  color: var(--primary-color);
  text-decoration: underline;
  text-decoration-color: color-mix(in srgb, var(--primary-color) 50%, transparent);
  text-underline-offset: 2px;
}

/* ============================================================================ */
/* Responsive: show mobile TOC elements on small viewports                      */
/* Must be AFTER default display:none rules to win in the cascade               */
/* ============================================================================ */

@media (max-width: 1100px) {
  .toc-mobile-toggle {
    display: flex;
  }

  .toc-mobile-backdrop {
    display: block;
  }

  .toc-mobile-sidebar {
    display: flex;
  }
}