/* ======================================
   Left Sidebar
   ====================================== */
#left-sidebar {
  width: var(--sidebar-width);
  background: var(--bg-secondary);
  border-right: 1px solid var(--border-primary);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
  overflow: hidden;
  transition: width var(--transition-smooth), opacity var(--transition-smooth);
  z-index: 30;
}

#left-sidebar.collapsed {
  width: 0;
  opacity: 0;
  pointer-events: none;
}

/* Sidebar Tabs */
.sidebar-tabs {
  display: flex;
  border-bottom: 1px solid var(--border-primary);
  padding: var(--space-1);
  gap: 2px;
  flex-shrink: 0;
}

.sidebar-tab {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  padding: var(--space-2) var(--space-2);
  border-radius: var(--radius-sm);
  font-size: var(--font-xs);
  font-weight: 500;
  color: var(--text-muted);
  cursor: pointer;
  transition: all var(--transition-fast);
  user-select: none;
}

.sidebar-tab:hover {
  color: var(--text-secondary);
  background: var(--bg-hover);
}

.sidebar-tab.active {
  color: var(--accent);
  background: var(--accent-soft);
}

.sidebar-tab svg {
  width: 14px;
  height: 14px;
}

/* Sidebar Content Panels */
.sidebar-panel {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  padding: var(--space-2);
}

/* ======================================
   Page Thumbnails
   ====================================== */
#thumbnail-container {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding-bottom: var(--space-4);
}

.thumbnail-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-2);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition);
  border: 2px solid transparent;
  position: relative;
}

.thumbnail-item:hover {
  background: var(--bg-hover);
}

.thumbnail-item.active {
  background: var(--accent-soft);
  border-color: var(--accent);
}

.thumbnail-canvas-wrapper {
  width: 100%;
  aspect-ratio: 8.5/11;
  background: white;
  border-radius: var(--radius-sm);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  position: relative;
}

.thumbnail-canvas-wrapper canvas {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
}

.thumbnail-number {
  font-size: var(--font-xs);
  font-weight: 500;
  color: var(--text-muted);
}

.thumbnail-item.active .thumbnail-number {
  color: var(--accent);
  font-weight: 600;
}

/* Thumbnail actions overlay */
.thumbnail-actions {
  position: absolute;
  top: var(--space-2);
  right: var(--space-2);
  display: flex;
  gap: 2px;
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.thumbnail-item:hover .thumbnail-actions {
  opacity: 1;
}

.thumbnail-action-btn {
  width: 22px;
  height: 22px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-xs);
  background: var(--bg-glass);
  backdrop-filter: blur(8px);
  border: 1px solid var(--border-secondary);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.thumbnail-action-btn:hover {
  background: var(--bg-active);
  color: var(--text-primary);
}

.thumbnail-action-btn.danger:hover {
  background: var(--danger-soft);
  color: var(--danger);
}

.thumbnail-action-btn svg {
  width: 12px;
  height: 12px;
}

/* Drag placeholder for reorder */
.thumbnail-item.dragging {
  opacity: 0.4;
}

.thumbnail-item.drag-over-top {
  border-top: 2px solid var(--accent);
}

.thumbnail-item.drag-over-bottom {
  border-bottom: 2px solid var(--accent);
}

/* ======================================
   Bookmarks Panel
   ====================================== */
#bookmark-container {
  display: flex;
  flex-direction: column;
}

.bookmark-item {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: var(--font-sm);
  color: var(--text-secondary);
  transition: all var(--transition-fast);
}

.bookmark-item:hover {
  background: var(--bg-hover);
  color: var(--text-primary);
}

.bookmark-item svg {
  width: 14px;
  height: 14px;
  color: var(--accent);
  flex-shrink: 0;
}

.bookmark-item.level-1 { padding-left: var(--space-6); }
.bookmark-item.level-2 { padding-left: var(--space-10); }

.bookmark-empty {
  text-align: center;
  padding: var(--space-8) var(--space-4);
  color: var(--text-muted);
  font-size: var(--font-sm);
}

.bookmark-empty svg {
  width: 32px;
  height: 32px;
  margin: 0 auto var(--space-3);
  opacity: 0.3;
}

/* ======================================
   Right Properties Panel
   ====================================== */
#right-panel {
  width: var(--properties-width);
  background: var(--bg-secondary);
  border-left: 1px solid var(--border-primary);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
  overflow-y: auto;
  overflow-x: hidden;
  transition: width var(--transition-smooth), opacity var(--transition-smooth);
  z-index: 30;
}

#right-panel.collapsed {
  width: 0;
  opacity: 0;
  pointer-events: none;
}

.properties-header {
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--border-primary);
  font-size: var(--font-sm);
  font-weight: 600;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-shrink: 0;
}

.properties-section {
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--border-primary);
}

.properties-section-title {
  font-size: var(--font-xs);
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: var(--space-3);
}

.property-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  margin-bottom: var(--space-2);
}

.property-row:last-child {
  margin-bottom: 0;
}

.property-label {
  font-size: var(--font-sm);
  color: var(--text-secondary);
  white-space: nowrap;
  min-width: 60px;
}

.property-value {
  flex: 1;
  display: flex;
  align-items: center;
  gap: var(--space-1);
  justify-content: flex-end;
}

.property-value .input {
  max-width: 80px;
  text-align: right;
}

.property-btn-group {
  display: flex;
  gap: 2px;
}

.property-btn-group .tool-btn {
  width: 28px;
  height: 28px;
}

.property-btn-group .tool-btn svg {
  width: 14px;
  height: 14px;
}

/* No selection state */
.properties-empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-8) var(--space-4);
  text-align: center;
  color: var(--text-muted);
  gap: var(--space-3);
}

.properties-empty svg {
  width: 36px;
  height: 36px;
  opacity: 0.25;
}

.properties-empty p {
  font-size: var(--font-sm);
}

/* Sidebar Toggle Button */
.sidebar-toggle {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 16px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-primary);
  cursor: pointer;
  color: var(--text-muted);
  transition: all var(--transition);
  z-index: 35;
}

.sidebar-toggle:hover {
  background: var(--bg-hover);
  color: var(--text-primary);
}

.sidebar-toggle svg {
  width: 10px;
  height: 10px;
}

#left-sidebar-toggle {
  left: var(--sidebar-width);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  border-left: none;
}

#left-sidebar.collapsed ~ #left-sidebar-toggle,
#left-sidebar.collapsed + * + #left-sidebar-toggle {
  left: 0;
}

#right-sidebar-toggle {
  right: var(--properties-width);
  border-radius: var(--radius-sm) 0 0 var(--radius-sm);
  border-right: none;
}