/* ============================================
   SIDEBAR NAVIGATION - 3-Level Hierarchy
   ============================================ */

/* Sidebar header / branding */
.sidebar-header {
  padding: var(--space-5) var(--space-4);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  margin-bottom: var(--space-3);
}

.sidebar-title {
  font-size: var(--text-sm);
  font-weight: var(--weight-bold);
  color: var(--text-on-dark);
  line-height: var(--leading-tight);
  margin-bottom: var(--space-1);
}

.sidebar-subtitle {
  font-size: var(--text-xs);
  color: rgba(255, 255, 255, 0.5);
}

/* Search trigger in sidebar */
.sidebar-search {
  padding: var(--space-2) var(--space-4);
  margin-bottom: var(--space-2);
}

.search-trigger {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  width: 100%;
  padding: var(--space-2) var(--space-3);
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius-md);
  color: rgba(255, 255, 255, 0.5);
  font-size: var(--text-sm);
  transition: all var(--transition-fast);
}

.search-trigger:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.2);
}

.search-trigger svg {
  width: 16px;
  height: 16px;
  fill: currentColor;
  flex-shrink: 0;
}

.search-trigger .shortcut {
  margin-left: auto;
  font-size: var(--text-xs);
  opacity: 0.5;
}

/* Level 1 - Main sections */
.nav-list {
  padding: 0 var(--space-2);
}

.nav-l1 > .nav-link,
.nav-l1 > .nav-toggle {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  width: 100%;
  padding: var(--space-3) var(--space-3);
  color: var(--text-sidebar);
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  text-decoration: none;
  text-align: left;
}

.nav-l1 > .nav-link:hover,
.nav-l1 > .nav-toggle:hover {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-on-dark);
}

.nav-l1.active > .nav-link,
.nav-l1.active > .nav-toggle {
  background: rgba(255, 255, 255, 0.12);
  color: var(--text-sidebar-active);
  font-weight: var(--weight-semibold);
}

/* Nav icons */
.nav-icon {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  opacity: 0.7;
}

.nav-l1.active .nav-icon {
  opacity: 1;
}

/* Chevron for expandable items */
.nav-chevron {
  width: 16px;
  height: 16px;
  margin-left: auto;
  transition: transform var(--transition-base);
  opacity: 0.5;
  flex-shrink: 0;
}

.nav-l1.expanded > .nav-toggle .nav-chevron {
  transform: rotate(90deg);
  opacity: 0.8;
}

/* Level 2 - Sub-sections */
.nav-l2-list {
  overflow: hidden;
  max-height: 0;
  transition: max-height var(--transition-slow);
  padding-left: var(--space-2);
}

.nav-l1.expanded > .nav-l2-list {
  max-height: 2000px;
}

.nav-l2 > .nav-link,
.nav-l2 > .nav-toggle {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  width: 100%;
  padding: var(--space-2) var(--space-3) var(--space-2) var(--space-8);
  color: rgba(255, 255, 255, 0.55);
  font-size: var(--text-xs);
  font-weight: var(--weight-medium);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
  text-decoration: none;
  text-align: left;
}

.nav-l2 > .nav-link:hover,
.nav-l2 > .nav-toggle:hover {
  color: var(--text-sidebar);
  background: rgba(255, 255, 255, 0.05);
}

.nav-l2.active > .nav-link,
.nav-l2.active > .nav-toggle {
  color: var(--text-on-dark);
}

.nav-l2 .nav-chevron {
  width: 12px;
  height: 12px;
}

.nav-l2.expanded > .nav-toggle .nav-chevron {
  transform: rotate(90deg);
}

/* Level 3 - Individual items */
.nav-l3-list {
  overflow: hidden;
  max-height: 0;
  transition: max-height var(--transition-slow);
}

.nav-l2.expanded > .nav-l3-list {
  max-height: 3000px;
}

.nav-l3 > .nav-link {
  display: block;
  padding: var(--space-1) var(--space-3) var(--space-1) calc(var(--space-8) + var(--space-4));
  color: rgba(255, 255, 255, 0.45);
  font-size: var(--text-xs);
  font-weight: var(--weight-normal);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
  text-decoration: none;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.nav-l3 > .nav-link:hover {
  color: var(--text-sidebar);
  background: rgba(255, 255, 255, 0.05);
}

.nav-l3.active > .nav-link {
  color: var(--color-seafoam);
  font-weight: var(--weight-medium);
}

/* Sidebar close button (mobile only) */
.sidebar-close {
  display: none;
  position: absolute;
  top: var(--space-3);
  right: var(--space-3);
  color: var(--text-sidebar);
  padding: var(--space-2);
  border-radius: var(--radius-sm);
}

.sidebar-close:hover {
  background: rgba(255, 255, 255, 0.1);
}

@media (max-width: 768px) {
  .sidebar-close {
    display: block;
  }
}

/* Divider between nav groups */
.nav-divider {
  height: 1px;
  background: rgba(255, 255, 255, 0.08);
  margin: var(--space-3) var(--space-4);
}