/* ============================================================
   sidebar.css — Knowledge Base Wiki Navigation Sidebar
   Color-coded folder tree grouped by meta-categories.
   Dark/light mode support via CSS custom properties (canvas.css).
   ============================================================ */

/* ----------------------------------------------------------
   Sidebar Container
   ---------------------------------------------------------- */

.sidebar {
  position: fixed;
  left: 0;
  top: 0;
  bottom: 0;
  width: var(--sidebar-width, 280px);
  background: var(--surface);
  border-right: 1px solid var(--border);
  z-index: 9998;
  display: flex;
  flex-direction: column;
  transition: transform 0.3s ease;
  font-family: 'IBM Plex Mono', monospace;
}

.sidebar.collapsed {
  transform: translateX(-240px);
}

/* ----------------------------------------------------------
   Sidebar Header
   ---------------------------------------------------------- */

.sidebar-header {
  height: 54px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 12px;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.sidebar-title {
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-dim);
}

.sidebar-toggle,
.sidebar-theme-btn {
  width: 28px;
  height: 28px;
  border: none;
  background: transparent;
  color: var(--text-dim);
  cursor: pointer;
  border-radius: 4px;
  font-size: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s;
}

.sidebar-toggle:hover,
.sidebar-theme-btn:hover {
  background: var(--surface-hover);
}

/* Collapsed state — only thin strip with toggle visible */

.sidebar.collapsed .sidebar-toggle {
  position: absolute;
  right: 6px;
  top: 13px;
}

.sidebar.collapsed .sidebar-title {
  display: none;
}

.sidebar.collapsed .sidebar-search {
  display: none;
}

.sidebar.collapsed .sidebar-tree {
  display: none;
}

.sidebar.collapsed .sidebar-nav-links {
  display: none;
}

.sidebar.collapsed .sidebar-theme-btn {
  display: none;
}

/* ----------------------------------------------------------
   Sidebar Navigation Links (Home / Canvas)
   ---------------------------------------------------------- */

.sidebar-nav-links {
  display: flex;
  flex-direction: column;
  padding: 8px 8px 0;
  gap: 2px;
  flex-shrink: 0;
}

.sidebar-nav-link {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 10px;
  border-radius: 6px;
  font-size: 12px;
  font-weight: 500;
  color: var(--text-dim);
  text-decoration: none;
  transition: background 0.15s, color 0.15s;
  cursor: pointer;
}

.sidebar-nav-link:hover {
  background: var(--surface-hover);
  color: var(--text);
}

.sidebar-nav-link.active {
  background: var(--accent-dim);
  color: var(--accent);
}

.sidebar-nav-link .nav-icon {
  font-size: 14px;
  line-height: 1;
}

/* ----------------------------------------------------------
   Sidebar Search / Filter
   ---------------------------------------------------------- */

.sidebar-search {
  padding: 8px 12px;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.sidebar-filter {
  width: 100%;
  height: 30px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0 10px;
  color: var(--text);
  font-family: inherit;
  font-size: 12px;
  outline: none;
  transition: border-color 0.2s;
  box-sizing: border-box;
}

.sidebar-filter::placeholder {
  color: var(--text-dim);
}

.sidebar-filter:focus {
  border-color: var(--accent);
}

/* ----------------------------------------------------------
   Sidebar Tree — uses system sans-serif for readability
   ---------------------------------------------------------- */

.sidebar-tree {
  flex: 1;
  overflow-y: auto;
  padding: 4px 0 16px;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
}

.sidebar-tree::-webkit-scrollbar {
  width: 4px;
}

.sidebar-tree::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 2px;
}

/* ----------------------------------------------------------
   Meta-Category Section Headers (non-collapsible dividers)
   ---------------------------------------------------------- */

.sidebar-section-header {
  padding: 16px 12px 4px;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 10px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-dim);
  border-bottom: 1px solid var(--border);
  margin-bottom: 4px;
  user-select: none;
}

/* First section header needs less top padding */
.sidebar-section-header:first-child {
  padding-top: 8px;
}

/* ----------------------------------------------------------
   Folder Items
   ---------------------------------------------------------- */

.sidebar-folder {
  margin: 0;
  padding: 0;
}

/* Top-level folder headers (depth 1) */
.sidebar-folder-header {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 5px 12px;
  cursor: pointer;
  transition: background 0.1s;
  user-select: none;
  font-size: 13px;
  font-weight: 500;
  border-left: 3px solid var(--folder-color, var(--border));
  border-radius: 0 4px 4px 0;
}

.sidebar-folder-header:hover {
  background: var(--surface-hover);
}

.sidebar-folder-header:hover .folder-name {
  color: var(--text-bright);
}

/* Folder chevron (expand/collapse indicator) */

.sidebar-folder-header .folder-chevron {
  width: 14px;
  font-size: 10px;
  color: var(--folder-color, var(--text-dim));
  transition: transform 0.15s;
  flex-shrink: 0;
}

.sidebar-folder-header.expanded .folder-chevron {
  transform: rotate(90deg);
}

/* Folder name */

.sidebar-folder-header .folder-name {
  flex: 1;
  color: var(--text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  transition: color 0.1s;
}

/* Folder item count badge */

.sidebar-folder-header .folder-count {
  font-size: 9px;
  color: var(--text-dim);
  background: var(--bg);
  padding: 1px 6px;
  border-radius: 8px;
  font-family: 'IBM Plex Mono', monospace;
}

/* ----------------------------------------------------------
   Folder Children (expand/collapse via adjacent sibling)
   ---------------------------------------------------------- */

.sidebar-folder-children {
  display: none;
  padding-left: 12px;
}

.sidebar-folder-header.expanded + .sidebar-folder-children {
  display: block;
}

/* ----------------------------------------------------------
   Page Items (leaf nodes)
   ---------------------------------------------------------- */

.sidebar-page {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 4px 12px 4px 16px;
  cursor: pointer;
  transition: background 0.1s;
  font-size: 12.5px;
  line-height: 1.4;
  text-decoration: none;
  color: var(--text);
}

.sidebar-page:hover {
  background: var(--surface-hover);
}

.sidebar-page.active {
  background: var(--accent-dim);
  color: var(--accent);
  border-radius: 4px;
}

/* Colored dot inherits folder hue */

.sidebar-page .page-dot {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  flex-shrink: 0;
  background: var(--folder-color, var(--text-dim));
  opacity: 0.7;
}

.sidebar-page.active .page-dot {
  background: var(--accent);
  opacity: 1;
}

.sidebar-page .page-name {
  flex: 1;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sidebar-page .page-category {
  font-size: 10px;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  flex-shrink: 0;
  font-family: 'IBM Plex Mono', monospace;
}

/* ----------------------------------------------------------
   Nested Folder Indentation & Depth-Specific Styling
   ---------------------------------------------------------- */

/* Depth 2 — sub-folders */
.sidebar-folder .sidebar-folder .sidebar-folder-header {
  padding-left: 24px;
  font-size: 12px;
  font-weight: 400;
  border-left-width: 2px;
}

.sidebar-folder .sidebar-folder .sidebar-page {
  padding-left: 28px;
}

/* Depth 3 — sub-sub-folders */
.sidebar-folder .sidebar-folder .sidebar-folder .sidebar-folder-header {
  padding-left: 36px;
  font-size: 12px;
  font-weight: 400;
  border-left-width: 2px;
  color: var(--text-dim);
}

.sidebar-folder .sidebar-folder .sidebar-folder .sidebar-folder-header .folder-name {
  color: var(--text-dim);
}

.sidebar-folder .sidebar-folder .sidebar-folder .sidebar-page {
  padding-left: 40px;
}

/* ----------------------------------------------------------
   Light Theme Adjustments
   ---------------------------------------------------------- */

[data-theme="light"] .sidebar {
  background: var(--surface);
}

[data-theme="light"] .sidebar-section-header {
  color: var(--text-dim);
  border-bottom-color: var(--border);
}

[data-theme="light"] .sidebar-folder-header:hover {
  background: var(--surface-hover);
}

[data-theme="light"] .sidebar-page:hover {
  background: var(--surface-hover);
}

[data-theme="light"] .sidebar-page.active {
  background: var(--accent-dim);
  color: var(--accent);
}

[data-theme="light"] .sidebar-filter {
  background: var(--bg);
  border-color: var(--border);
}

[data-theme="light"] .sidebar-tree::-webkit-scrollbar-thumb {
  background: var(--border);
}

/* ----------------------------------------------------------
   Responsive — Mobile Overlay
   ---------------------------------------------------------- */

@media (max-width: 768px) {
  .sidebar {
    position: fixed;
    transform: translateX(-100%);
    z-index: 10000;
    width: var(--sidebar-width, 280px);
    box-shadow: none;
  }

  .sidebar.open {
    transform: translateX(0);
    box-shadow: 4px 0 24px rgba(0, 0, 0, 0.25);
  }

  .sidebar.collapsed {
    transform: translateX(-100%);
  }

  /* Backdrop overlay when sidebar is open on mobile */
  .sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.45);
    z-index: 9999;
    transition: opacity 0.3s ease;
    opacity: 0;
  }

  .sidebar-overlay.visible {
    display: block;
    opacity: 1;
  }
}

/* Overlay hidden by default on larger screens */
@media (min-width: 769px) {
  .sidebar-overlay {
    display: none !important;
  }
}