/* ==========================================================
   toc-collapse.css
   1. サイドバー上部の全章リンク
   2. アクティブページのTOC折りたたみ
   3. インデント調整
   ========================================================== */

/* ==========================================================
   サイドバー上部の章リンク（囲み枠）
   ========================================================== */
.sidebar-chapters {
  padding: 0.4rem 0.6rem 0.5rem;
  margin: 0.4rem 0.6rem 0.8rem;
  border: 1px solid var(--md-default-fg-color--lightest);
  border-radius: 6px;
  background-color: rgba(0, 0, 0, 0.015);
}

[data-md-color-scheme="slate"] .sidebar-chapters {
  background-color: rgba(255, 255, 255, 0.02);
}

.sidebar-chapter-link {
  display: block;
  padding: 0.3rem 0.5rem;
  margin: 0.1rem 0;
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--md-default-fg-color--light);
  text-decoration: none;
  border-radius: 4px;
  transition: background-color 0.15s ease, color 0.15s ease;
  line-height: 1.4;
}

.sidebar-chapter-link:hover {
  background-color: rgba(0, 0, 0, 0.04);
  color: var(--md-default-fg-color);
}

[data-md-color-scheme="slate"] .sidebar-chapter-link:hover {
  background-color: rgba(255, 255, 255, 0.06);
}

/* アクティブな章（現在のタブ） */
.sidebar-chapter-link--active {
  color: var(--md-primary-fg-color);
  background-color: var(--md-accent-fg-color--transparent);
}

.sidebar-chapter-link--active:hover {
  color: var(--md-primary-fg-color);
}

/* ==========================================================
   TOC折りたたみトグル
   ========================================================== */
.toc-collapsible > a.md-nav__link {
  cursor: pointer;
}

.toc-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.2em;
  height: 1.2em;
  margin-right: 0.15em;
  flex-shrink: 0;
  cursor: pointer;
  border-radius: 3px;
  transition: background-color 0.15s ease;
}

.toc-toggle:hover {
  background-color: rgba(0, 0, 0, 0.06);
}

[data-md-color-scheme="slate"] .toc-toggle:hover {
  background-color: rgba(255, 255, 255, 0.08);
}

.toc-toggle::before {
  content: "";
  display: block;
  width: 0;
  height: 0;
  border-style: solid;
  border-width: 4px 0 4px 6px;
  border-color: transparent transparent transparent var(--md-default-fg-color--light);
  transition: transform 0.2s ease;
}

.toc-expanded > a.md-nav__link .toc-toggle::before {
  transform: rotate(90deg);
}

.toc-collapsed > a.md-nav__link .toc-toggle::before {
  transform: rotate(0deg);
}

/* TOC ナビの表示/非表示 */
.toc-collapsible > nav.md-nav {
  overflow: hidden;
  transition: max-height 0.25s ease, opacity 0.2s ease;
}

.toc-expanded > nav.md-nav {
  max-height: 5000px;
  opacity: 1;
}

.toc-collapsed > nav.md-nav {
  max-height: 0;
  opacity: 0;
}

/* ==========================================================
   サブページとTOCのインデント調整
   ========================================================== */
.md-sidebar--primary .md-nav .md-nav .md-nav__link {
  padding-left: 1.8rem;
}

.md-sidebar--primary .md-nav .md-nav .md-nav .md-nav__link {
  padding-left: 2.4rem;
}

.md-sidebar--primary .md-nav .md-nav .md-nav .md-nav .md-nav__link {
  padding-left: 3.0rem;
}