/* ==========================================================================
   GCBoK Sidebar Navigation — Hamburger-Menu + Two-Level Sidebar + Scroll-Spy
   ========================================================================== */

/* --- Hamburger Button (im Header) --- */
.hamburger {
  display: flex;
  align-items: center;
  justify-content: center;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--sp-2);
  border-radius: var(--radius);
  color: var(--text-body);
  transition: background 120ms ease, color 120ms ease;
}
.hamburger:hover { background: var(--c-slate-100); color: var(--text-strong); }
.hamburger:focus-visible { outline: 2px solid var(--c-green-deep); outline-offset: 2px; }

.hamburger__bars {
  display: inline-block;
  width: 18px;
  height: 14px;
  position: relative;
}
.hamburger__bars span {
  display: block;
  position: absolute;
  height: 2px;
  width: 100%;
  background: currentColor;
  border-radius: 1px;
  transition: transform 200ms ease, opacity 150ms ease, top 200ms ease;
}
.hamburger__bars span:nth-child(1) { top: 0; }
.hamburger__bars span:nth-child(2) { top: 6px; }
.hamburger__bars span:nth-child(3) { top: 12px; }

/* X-Animation wenn offen */
.hamburger--active .hamburger__bars span:nth-child(1) {
  top: 6px;
  transform: rotate(45deg);
}
.hamburger--active .hamburger__bars span:nth-child(2) {
  opacity: 0;
}
.hamburger--active .hamburger__bars span:nth-child(3) {
  top: 6px;
  transform: rotate(-45deg);
}

/* --- Sidebar Drawer --- */
.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  width: 300px;
  max-width: 85vw;
  height: 100vh;
  height: 100dvh;
  background: var(--c-paper);
  border-right: 1px solid var(--c-line);
  z-index: 1000;
  overflow-y: auto;
  transform: translateX(-100%);
  transition: transform 250ms cubic-bezier(0.4, 0, 0.2, 1);
  display: flex;
  flex-direction: column;
}
.sidebar--open { transform: translateX(0); }
.sidebar--persisted { box-shadow: 2px 0 8px rgba(0,0,0,0.08); }

/* Backdrop (nur bei Overlay-Modus) */
.sidebar-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.35);
  z-index: 999;
  opacity: 0;
  visibility: hidden;
  transition: opacity 200ms ease, visibility 200ms ease;
}
.sidebar-backdrop--visible { opacity: 1; visibility: visible; }

/* Sidebar Header */
.sidebar__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--sp-3) var(--sp-4);
  border-bottom: 1px solid var(--c-line);
  position: sticky;
  top: 0;
  background: var(--c-paper);
  z-index: 1;
}
.sidebar__title {
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--text-strong);
  margin: 0;
}
.sidebar__close {
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--sp-1);
  border-radius: var(--radius);
  color: var(--text-muted);
  transition: background 120ms ease, color 120ms ease;
}
.sidebar__close:hover { background: var(--c-slate-100); color: var(--text-strong); }

/* Sidebar Sections */
.sidebar__section {
  padding: var(--sp-2) 0;
  border-bottom: 1px solid var(--c-line);
}
.sidebar__section:last-child { border-bottom: none; }

.sidebar__label {
  display: block;
  font-size: var(--fs-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  padding: var(--sp-2) var(--sp-4);
  margin: 0;
}

/* Level 1 — Site-Navigation */
.sidebar__nav { list-style: none; padding: 0; margin: 0; }
.sidebar__nav li { margin: 0; }
.sidebar__nav a {
  display: flex;
  align-items: baseline;
  gap: var(--sp-2);
  padding: var(--sp-2) var(--sp-4);
  font-size: var(--fs-sm);
  color: var(--text-body);
  text-decoration: none;
  border-left: 3px solid transparent;
  transition: background 100ms ease, color 100ms ease, border-color 100ms ease;
}
.sidebar__nav a:hover {
  background: var(--c-slate-50);
  color: var(--text-strong);
  text-decoration: none;
}
.sidebar__nav a.is-active {
  border-left-color: var(--c-green-deep);
  background: var(--c-green-soft);
  color: var(--c-green-deep);
  font-weight: 600;
}
.sidebar__nav .nav-idx {
  font-size: var(--fs-xs);
  color: var(--text-muted);
  min-width: 1.5em;
  text-align: right;
  font-variant-numeric: tabular-nums;
}
.sidebar__nav a.is-active .nav-idx { color: var(--c-green-deep); }

/* Level 2 — Auf dieser Seite (TOC) */
.sidebar__toc { list-style: none; padding: 0; margin: 0; }
.sidebar__toc li { margin: 0; }
.sidebar__toc a {
  display: block;
  padding: var(--sp-1) var(--sp-4) var(--sp-1) var(--sp-6);
  font-size: var(--fs-xs);
  color: var(--text-muted);
  text-decoration: none;
  border-left: 3px solid transparent;
  transition: color 100ms ease, border-color 100ms ease;
  line-height: 1.4;
}
.sidebar__toc a:hover { color: var(--text-strong); text-decoration: none; }
.sidebar__toc a.is-active {
  border-left-color: var(--c-amber);
  color: var(--c-amber-deep);
  font-weight: 600;
}

/* --- Body Shift (wenn Sidebar permanent auf Desktop) --- */
body.sidebar-persisted { padding-left: 300px; }
body.sidebar-persisted .site-header { left: 300px; }

/* --- Prev/Next Navigation am Content-Ende --- */
.page-nav {
  display: flex;
  justify-content: space-between;
  align-items: stretch;
  gap: var(--sp-4);
  margin-top: var(--sp-12);
  padding-top: var(--sp-6);
  border-top: 1px solid var(--c-line);
}
.page-nav__link {
  display: flex;
  flex-direction: column;
  gap: var(--sp-1);
  padding: var(--sp-3) var(--sp-4);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--text-body);
  transition: border-color 120ms ease, background 120ms ease;
  flex: 1;
  max-width: 45%;
}
.page-nav__link:hover {
  border-color: var(--c-green-deep);
  background: var(--c-green-soft);
  text-decoration: none;
}
.page-nav__label {
  font-size: var(--fs-xs);
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.page-nav__title { font-size: var(--fs-sm); font-weight: 600; color: var(--text-strong); }
.page-nav__link--next { text-align: right; }

/* --- Dark Mode --- */
:root[data-theme="dark"] .sidebar { background: var(--c-slate-900); border-right-color: var(--c-slate-700); }
:root[data-theme="dark"] .sidebar__header { background: var(--c-slate-900); border-bottom-color: var(--c-slate-700); }
:root[data-theme="dark"] .sidebar__section { border-bottom-color: var(--c-slate-700); }
:root[data-theme="dark"] .sidebar__nav a:hover { background: rgba(255,255,255,0.04); }
:root[data-theme="dark"] .sidebar__nav a.is-active { background: rgba(10,127,92,0.2); }
:root[data-theme="dark"] .page-nav__link { border-color: var(--c-slate-700); }
:root[data-theme="dark"] .page-nav__link:hover { border-color: var(--c-green-deep); background: rgba(10,127,92,0.15); }

/* --- Responsive --- */
@media (min-width: 1024px) {
  /* Auf Desktop kann Sidebar permanent eingeblendet sein (via JS localStorage) */
  body.sidebar-persisted .sidebar {
    transform: translateX(0);
    box-shadow: none;
  }
  body.sidebar-persisted .sidebar-backdrop { display: none; }
}

@media (max-width: 1023px) {
  /* Mobile: immer Overlay-Modus, nie permanent */
  body.sidebar-persisted { padding-left: 0; }
  body.sidebar-persisted .site-header { left: 0; }
}