/* ==========================================================================
       1. BASE STYLES & CSS RESET
       ========================================================================== */
    * { box-sizing: border-box; }

    /* ==========================================================================
       2. CSS CUSTOM PROPERTIES (DESIGN TOKENS)
       ========================================================================== */
    :root {
      /* Brand Colors */
      --color-kvot-bright: #f3b87b;      /* Beige */
      --color-kvot-accent: #bb6c5d;      /* Red-brown */
      --color-kvot-background: #352921; /* Dark brown */
      --color-kvot-primary: #344126;     /* Dark green */
      
      /* Panel & Surface Colors */
      --color-panel-bg: #faf8f6;
      --color-panel-border: #e5ddd5;
      --color-hover-bg: #f5ede5;
      --color-selected-bg: #ede3d8;
      
      /* Text Colors */
      --color-text-primary: #2d2416;
      --color-text-secondary: #6b5d4f;
      --color-text-muted: #9b8d7f;
      --color-selected-text: #2d2416;
    }

    [data-theme="dark"] {
      --color-panel-bg: #2a221b;
      --color-panel-border: #4a3f35;
      --color-hover-bg: #3a3028;
      --color-selected-bg: #4a3f35;
      --color-text-primary: #e8ddd0;
      --color-text-secondary: #b8a898;
      --color-text-muted: #8a7d6f;
      --color-selected-text: #e8ddd0;
    }

    /* ==========================================================================
       3. LAYOUT
       ========================================================================== */
    body { 
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; 
      margin: 0; 
      padding: 0;
      padding-top: 42px;
      background: var(--bg-primary, #ebe3db); 
      height: 100vh;
      display: flex;
      flex-direction: column;
      overflow: hidden;
      color: var(--color-text-primary);
      transition: background-color 0.3s ease, color 0.3s ease;
    }

    /* ==========================================================================
       4. DRAG & DROP OVERLAY
       ========================================================================== */
    #dropOverlay {
      position: fixed;
      top: 0;
      left: 0;
      right: 0;
      bottom: 0;
      background: rgba(243, 184, 123, 0.15);
      border: 4px dashed var(--color-kvot-bright);
      display: none;
      align-items: center;
      justify-content: center;
      z-index: 9999;
      pointer-events: none;
    }
    
    #dropOverlay.active {
      display: flex;
    }
    
    #dropOverlay .message {
      background: var(--color-panel-bg);
      padding: 40px;
      border-radius: 12px;
      box-shadow: 0 8px 24px rgba(53, 41, 33, 0.25);
      font-size: 24px;
      color: var(--color-kvot-primary);
      font-weight: 600;
    }

    /* ==========================================================================
       5. FILE TABS & HEADER
       ========================================================================== */
    header, footer {
      box-sizing: content-box;
    }

    header {
      grid-template-columns: 60px auto 1fr 80px;
      z-index: 1000000000;
    }

    .tabs-container {
      display: flex;
      align-items: flex-end;
      gap: 4px;
      overflow-x: auto;
      overflow-y: hidden;
      margin-left: 12px;
      position: relative;
      top: 3px;
    }

    #fileTabs {
      display: flex;
      gap: 4px;
      flex: 1;
      overflow-x: auto;
      overflow-y: hidden;
    }
    
    .file-tab {
      display: flex;
      align-items: center;
      gap: 6px;
      padding: 4px 10px;
      background: rgba(255, 255, 255, 0.1);
      border: 1px solid var(--color-kvot-accent);
      border-bottom: none;
      border-radius: 4px 4px 0 0;
      cursor: pointer;
      user-select: none;
      font-size: 12px;
      transition: all 0.2s;
      position: relative;
      max-width: 160px;
      color: rgba(243, 184, 123, 0.7);
      white-space: nowrap;
    }
    
    .file-tab:hover {
      background: rgba(255, 255, 255, 0.15);
      color: var(--color-kvot-bright);
    }
    
    .file-tab.enabled {
      background: var(--color-kvot-bright);
      color: var(--color-kvot-background);
      border-color: var(--color-kvot-bright);
    }
    
    .file-tab.enabled:hover {
      background: #f5c690;
    }
    
    .file-tab.disabled {
      opacity: 0.5;
      background: rgba(255, 255, 255, 0.05);
    }
    
    .file-tab.disabled:hover {
      opacity: 0.7;
    }
    
    .file-tab-name {
      flex: 1;
      overflow: hidden;
      text-overflow: ellipsis;
      white-space: nowrap;
    }
    
    .file-tab-close {
      width: 16px;
      height: 16px;
      border-radius: 3px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 14px;
      line-height: 1;
      flex-shrink: 0;
      transition: background 0.2s;
    }
    
    .file-tab-close:hover {
      background: rgba(0, 0, 0, 0.2);
    }
    
    .file-tab.enabled .file-tab-close:hover {
      background: rgba(53, 41, 33, 0.15);
    }

    .file-tab-tooltip {
      position: fixed;
      z-index: 2147483647;
      max-width: 360px;
      min-width: 180px;
      max-height: 55vh;
      overflow: auto;
      pointer-events: none;
      background: var(--color-panel-bg);
      border: 1px solid var(--color-panel-border);
      border-radius: 8px;
      box-shadow: 0 8px 22px rgba(0, 0, 0, 0.22);
      padding: 8px 10px;
      color: var(--color-text-primary);
      font-size: 12px;
      line-height: 1.35;
      word-break: break-word;
      overflow-wrap: anywhere;
    }

    .file-tab-tooltip-title {
      font-weight: 600;
      margin-bottom: 6px;
      color: var(--color-kvot-primary);
      border-bottom: 1px solid var(--color-panel-border);
      padding-bottom: 4px;
    }

    .file-tab-tooltip-info {
      color: var(--color-text-primary);
    }

    .file-tab-tooltip-info > :first-child {
      margin-top: 0;
    }

    .file-tab-tooltip-info > :last-child {
      margin-bottom: 0;
    }

    .file-tab-tooltip-info p,
    .file-tab-tooltip-info ul,
    .file-tab-tooltip-info ol,
    .file-tab-tooltip-info pre,
    .file-tab-tooltip-info blockquote {
      margin: 0.3em 0;
    }

    .file-tab-tooltip-info pre,
    .file-tab-tooltip-info code {
      white-space: pre-wrap;
      word-break: break-word;
    }

    .chart-bg-tooltip {
      position: fixed;
      z-index: 2147483647;
      pointer-events: none;
      padding: 6px 10px;
      border-radius: 6px;
      border: 1px solid var(--color-border);
      background: var(--color-panel-bg);
      color: var(--color-text-primary);
      font-size: 12px;
      font-weight: 600;
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.16);
      white-space: nowrap;
    }

    .tree-info-tooltip {
      position: fixed;
      z-index: 2147483647;
      pointer-events: none;
      max-width: 420px;
      max-height: 55vh;
      overflow: auto;
      padding: 8px 10px;
      border-radius: 8px;
      border: 1px solid var(--color-panel-border);
      background: var(--color-panel-bg);
      color: var(--color-text-primary);
      font-size: 12px;
      line-height: 1.35;
      box-shadow: 0 8px 20px rgba(0, 0, 0, 0.22);
      word-break: break-word;
      overflow-wrap: anywhere;
    }

    .tree-info-tooltip > :first-child {
      margin-top: 0;
    }

    .tree-info-tooltip > :last-child {
      margin-bottom: 0;
    }
    
    .add-file-btn {
      padding: 4px 10px;
      background: var(--color-kvot-primary);
      color: var(--color-kvot-bright);
      border: none;
      border-radius: 4px 4px 0 0;
      cursor: pointer;
      font-size: 12px;
      font-weight: 500;
      line-height: 1.2;
      box-sizing: border-box;
      transition: background 0.2s;
      margin-left: auto;
      white-space: nowrap;
    }
    
    .add-file-btn:hover {
      background: #405533;
    }

    .url-file-btn {
      margin-left: 4px;
    }

    /* URL dialog overlay & modal */
    .url-dialog-overlay {
      position: fixed;
      inset: 0;
      background: rgba(0,0,0,0.45);
      z-index: 9999;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .url-dialog {
      background: var(--color-panel-bg);
      border: 1px solid var(--color-panel-border);
      border-radius: 10px;
      padding: 24px 28px;
      width: 460px;
      max-width: 92vw;
      box-shadow: 0 8px 32px rgba(0,0,0,0.25);
    }
    .url-dialog h3 {
      margin: 0 0 6px;
      font-size: 16px;
      color: var(--color-kvot-primary);
    }
    .url-dialog p {
      margin: 0 0 14px;
      font-size: 12.5px;
      color: var(--color-text-secondary);
    }
    .url-dialog p code {
      background: var(--color-hover-bg);
      padding: 1px 5px;
      border-radius: 3px;
      font-size: 11.5px;
    }
    .url-input {
      width: 100%;
      box-sizing: border-box;
      padding: 9px 12px;
      font-size: 13px;
      border: 1px solid var(--color-panel-border);
      border-radius: 6px;
      background: var(--color-hover-bg);
      color: var(--color-text-secondary);
      outline: none;
      transition: border-color 0.2s;
    }
    .url-input:focus {
      border-color: var(--color-kvot-accent);
    }
    .url-error {
      margin-top: 8px;
      font-size: 12px;
      color: #d63031;
    }
    .url-dialog-buttons {
      display: flex;
      justify-content: flex-end;
      gap: 8px;
      margin-top: 16px;
    }
    .url-btn {
      padding: 7px 18px;
      border: none;
      border-radius: 6px;
      font-size: 13px;
      font-weight: 500;
      cursor: pointer;
      transition: background 0.2s;
    }
    .url-btn-cancel {
      background: var(--color-hover-bg);
      color: var(--color-text-secondary);
    }
    .url-btn-cancel:hover {
      background: var(--color-panel-border);
    }
    .url-btn-load {
      background: var(--color-kvot-primary);
      color: var(--color-kvot-bright);
    }
    .url-btn-load:hover {
      background: #405533;
    }
    .url-btn-load:disabled {
      opacity: 0.6;
      cursor: not-allowed;
    }

    .sample-data-list {
      max-height: 300px;
      overflow-y: auto;
      margin: 12px 0;
    }
    .sample-data-item {
      display: flex;
      align-items: center;
      gap: 8px;
      padding: 8px 10px;
      border-radius: 4px;
      cursor: pointer;
      transition: background 0.15s;
    }
    .sample-data-item:hover {
      background: rgba(128, 128, 128, 0.1);
    }
    .sample-data-item input[type="checkbox"] {
      flex-shrink: 0;
    }
    .sample-data-item label {
      cursor: pointer;
      font-size: 13px;
      word-break: break-all;
    }
    .sample-data-empty {
      padding: 16px;
      text-align: center;
      color: var(--color-text-muted, #888);
      font-size: 13px;
    }

    /* ==========================================================================
       6. MAIN LAYOUT & PANELS
       ========================================================================== */
    .container { 
      display: flex; 
      gap: 4px;
      padding: 16px;
      flex: 1;
      overflow: hidden;
    }

    #leftPanel {
      flex: 0 0 350px;
      min-width: 150px;
      max-width: 60%;
    }

    .resize-handle {
      width: 8px;
      cursor: col-resize;
      background: transparent;
      flex-shrink: 0;
      display: flex;
      align-items: stretch;
      justify-content: center;
    }

    .resize-handle::after {
      content: '';
      width: 3px;
      border-radius: 2px;
      transition: background 0.15s;
    }

    .resize-handle:hover::after,
    .resize-handle.active::after {
      background: var(--color-kvot-accent);
    }
    
    .panel { 
      background: var(--color-panel-bg);
      border-radius: 8px; 
      padding: 16px; 
      box-shadow: 0 2px 8px rgba(53, 41, 33, 0.1);
      border: 1px solid var(--color-panel-border);
      display: flex;
      flex-direction: column;
      overflow: hidden;
      flex: 1;
      min-width: 0;
    }
    
    .panel h3 {
      margin: 0 0 12px 0;
      color: var(--color-kvot-primary);
      font-size: 16px;
      font-weight: 600;
    }

    /* Discrete light-bulb icon for multi-select hint — small, muted, hover-highlight */
    .show-hint-icon {
      color: var(--color-text-muted);
      opacity: 0.65;
      transition: opacity 0.15s ease, transform 0.12s ease;
      font-size: 14px;
      line-height: 1;
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }
    .show-hint-icon svg { width: 14px; height: 14px; }
    .show-hint-icon:hover {
      opacity: 1;
      transform: translateY(-1px);
      color: var(--color-text-primary);
    }
    
    .right-panel-content {
      flex: 1;
      overflow-y: auto;
      display: flex;
      flex-direction: column;
    }

    /* ==========================================================================
       7. TREE VIEW (File Structure)
       ========================================================================== */
    #tree { 
      flex: 1;
      overflow-y: auto; 
      font-size: 13px;
      padding: 4px;
    }
    
    /* Tree Item Base */
    .tree-item { 
      margin: 2px 0; 
      padding: 6px 8px;
      display: flex;
      align-items: center;
      cursor: pointer;
      border-radius: 4px;
      transition: all 0.15s ease;
      user-select: none;
      color: var(--color-text-primary);
    }
    
    .tree-item:hover {
      background: var(--color-hover-bg);
    }
    
    /* Tree Item - Group Type */
    .tree-item.group { 
      font-weight: 500;
      color: var(--color-kvot-primary);
    }
    
    .tree-item.group:hover {
      background: var(--color-hover-bg);
      color: var(--color-kvot-background);
    }
    
    .tree-item.group.expanded {
      background: var(--color-selected-bg);
      color: var(--color-kvot-background);
      border-left: 3px solid var(--color-kvot-accent);
      padding-left: 5px;
    }
    
    /* Tree Item - Dataset Type */
    .tree-item.dataset { 
      color: var(--color-text-secondary);
      font-size: 12px;
    }
    
    .tree-item.dataset:hover { 
      background: var(--color-hover-bg); 
      color: var(--color-text-primary);
    }
    
    .tree-item.dataset.selected { 
      background: var(--color-selected-bg); 
      color: var(--color-selected-text);
      font-weight: 500;
      border-left: 3px solid var(--color-kvot-accent);
      padding-left: 5px;
    }
    
    /* Tree Toggle Button */
    .tree-toggle {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 20px;
      height: 20px;
      margin-right: 4px;
      font-size: 10px;
      transition: transform 0.2s;
      flex-shrink: 0;
      color: var(--color-text-muted);
    }
    
    .tree-toggle.collapsed {
      transform: rotate(-90deg);
    }
    
    /* Tree Icons — SVG via mask-image for crisp, theme-aware colouring */
    .tree-icon {
      width: 18px;
      height: 18px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-right: 6px;
      flex-shrink: 0;
      position: relative;
    }

    .tree-icon::before {
      content: '';
      width: 16px;
      height: 16px;
      display: block;
      -webkit-mask-size: contain;
      mask-size: contain;
      -webkit-mask-repeat: no-repeat;
      mask-repeat: no-repeat;
      -webkit-mask-position: center;
      mask-position: center;
    }

    /* Folder icon — closed folder */
    .tree-icon.folder::before {
      background: var(--color-kvot-accent);
      -webkit-mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23000' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M22 19a2 2 0 0 1-2 2H4a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h5l2 3h9a2 2 0 0 1 2 2z'/%3E%3C/svg%3E");
      mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23000' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M22 19a2 2 0 0 1-2 2H4a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h5l2 3h9a2 2 0 0 1 2 2z'/%3E%3C/svg%3E");
    }

    /* Open-folder icon for expanded groups */
    .tree-item.group.expanded > .tree-icon.folder::before {
      -webkit-mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23000' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M22 19a2 2 0 0 1-2 2H4a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h5l2 3h9a2 2 0 0 1 2 2v1'/%3E%3Cpath d='M2 10l2.5 9H20l2-9H4.5'/%3E%3C/svg%3E");
      mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23000' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M22 19a2 2 0 0 1-2 2H4a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h5l2 3h9a2 2 0 0 1 2 2v1'/%3E%3Cpath d='M2 10l2.5 9H20l2-9H4.5'/%3E%3C/svg%3E");
    }

    /* Dataset icon — table / grid */
    .tree-icon.dataset::before {
      background: var(--color-kvot-bright);
      -webkit-mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23000' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M12 3h7a2 2 0 0 1 2 2v14a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h7'/%3E%3Cline x1='3' y1='9' x2='21' y2='9'/%3E%3Cline x1='3' y1='15' x2='21' y2='15'/%3E%3Cline x1='9' y1='3' x2='9' y2='21'/%3E%3C/svg%3E");
      mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23000' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M12 3h7a2 2 0 0 1 2 2v14a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h7'/%3E%3Cline x1='3' y1='9' x2='21' y2='9'/%3E%3Cline x1='3' y1='15' x2='21' y2='15'/%3E%3Cline x1='9' y1='3' x2='9' y2='21'/%3E%3C/svg%3E");
    }
    
    /* Tree Labels & Meta */
    .tree-label {
      flex: 1;
      overflow: hidden;
      text-overflow: ellipsis;
      white-space: nowrap;
    }
    
    .tree-meta {
      color: var(--color-text-muted);
      font-size: 11px;
      margin-left: 8px;
      flex-shrink: 0;
    }

    /* Link badge */
    .link-badge {
      display: inline-flex;
      align-items: center;
      margin-left: 4px;
      flex-shrink: 0;
      color: var(--color-kvot-accent);
      opacity: 0.8;
    }
    .link-badge.broken {
      color: #cc4444;
    }
    .link-badge.external {
      color: #9b6c5d;
    }
    .link-badge.soft {
      color: var(--color-kvot-primary);
    }

    /* Link tree icon variants */
    .tree-icon.broken-link::before {
      background: #cc4444;
      -webkit-mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23000' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M10 13a5 5 0 0 0 7.54.54l3-3a5 5 0 0 0-7.07-7.07l-1.72 1.71'/%3E%3Cpath d='M14 11a5 5 0 0 0-7.54-.54l-3 3a5 5 0 0 0 7.07 7.07l1.71-1.71'/%3E%3Cline x1='2' y1='2' x2='22' y2='22'/%3E%3C/svg%3E");
      mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23000' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M10 13a5 5 0 0 0 7.54.54l3-3a5 5 0 0 0-7.07-7.07l-1.72 1.71'/%3E%3Cpath d='M14 11a5 5 0 0 0-7.54-.54l-3 3a5 5 0 0 0 7.07 7.07l1.71-1.71'/%3E%3Cline x1='2' y1='2' x2='22' y2='22'/%3E%3C/svg%3E");
    }
    .tree-icon.external-link::before {
      background: var(--color-kvot-accent);
      -webkit-mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23000' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M18 13v6a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2V8a2 2 0 0 1 2-2h6'/%3E%3Cpolyline points='15 3 21 3 21 9'/%3E%3Cline x1='10' y1='14' x2='21' y2='3'/%3E%3C/svg%3E");
      mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23000' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M18 13v6a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2V8a2 2 0 0 1 2-2h6'/%3E%3Cpolyline points='15 3 21 3 21 9'/%3E%3Cline x1='10' y1='14' x2='21' y2='3'/%3E%3C/svg%3E");
    }
    .tree-item.broken-link {
      opacity: 0.6;
    }
    .tree-item.external-link .tree-meta {
      color: var(--color-kvot-accent);
      font-style: italic;
    }

    /* Link info in info panel */
    .info-section.link-info {
      border-left: 3px solid var(--color-kvot-accent);
      padding-left: 8px;
      margin-left: 4px;
    }
    .info-section.link-info.broken {
      border-left-color: #cc4444;
    }
    .info-section.link-info.external {
      border-left-color: var(--color-kvot-accent);
    }
    .info-section.link-info.soft {
      border-left-color: var(--color-kvot-primary);
    }

    /* PDF Histogram in info panel */
    .pdf-histogram-container {
      margin-top: 12px;
      padding: 10px;
      border: 1px solid var(--color-border);
      border-radius: 6px;
      background: var(--bg-surface, var(--color-hover-bg));
    }
    .pdf-histogram-container .info-label {
      margin-bottom: 6px;
    }
    .pdf-histogram-chart {
      width: 100%;
      height: 200px;
      border-radius: 4px;
      overflow: hidden;
    }
    .pdf-histogram-chart.pdf-histogram-small {
      height: 140px;
    }
    
    /* Tree Group Children Container */
    .tree-group-children {
      margin-left: 0;
      border-left: 2px solid var(--color-panel-border);
      padding-left: 4px;
      display: none;
    }
    
    .tree-group-children.expanded {
      display: block;
    }

    /* ==========================================================================
       8. SEARCH FUNCTIONALITY
       ========================================================================== */
    .search-container {
      position: relative;
      margin-bottom: 12px;
      display: none;
    }

    .search-container.visible {
      display: block;
    }

    .panel-heading {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }

    .tree-mode-toggle {
      display: inline-flex;
      align-items: stretch;
      border: 1px solid var(--color-panel-border);
      border-radius: 999px;
      background: var(--color-panel-bg);
      user-select: none;
      margin-top: -10px;
    }

    .tree-mode-toggle button {
      padding: 1px 7px;
      border: none;
      border-right: 1px solid var(--color-panel-border);
      background: transparent;
      color: var(--color-text-primary);
      cursor: pointer;
      font-size: 18px;
      line-height: 1;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: background 0.15s ease, color 0.15s ease;
      box-sizing: border-box;
    }

    .tree-mode-toggle button:last-child {
      border-right: none;
    }

    .tree-mode-toggle button:first-child {
      border-top-left-radius: 999px;
      border-bottom-left-radius: 999px;
    }

    .tree-mode-toggle button:last-child {
      border-top-right-radius: 999px;
      border-bottom-right-radius: 999px;
    }

    .tree-mode-toggle button.active {
      background: var(--color-kvot-bright);
      color: var(--color-kvot-background);
    }

    .tree-mode-toggle button:not(.active):hover {
      background: rgba(0,0,0,0.06);
    }

    .tree-mode-toggle button:focus {
      outline: none;
    }

    .tree-mode-toggle button:hover {
      transform: none;
      box-shadow: none;
    }

    [data-theme="dark"] .tree-mode-toggle button:not(.active) {
      color: rgba(255,255,255,0.6);
    }

    [data-theme="dark"] .tree-mode-toggle button:not(.active):hover {
      background: rgba(255,255,255,0.1);
    }

    [data-theme="light"] .tree-mode-toggle button:not(.active) {
      color: rgba(0,0,0,0.5);
    }

    .tree-mode-toggle button[disabled] {
      opacity: 0.4;
      cursor: default;
    }

    .tree-mode-toggle button[disabled]:hover {
      background: transparent;
    }

    /* Availability badge for union mode tree nodes */
    .tree-availability {
      display: inline-block;
      margin-left: 6px;
      padding: 0 5px;
      font-size: 10px;
      line-height: 16px;
      border-radius: 8px;
      background: var(--color-panel-border);
      color: var(--color-text-secondary);
      font-weight: 500;
      vertical-align: middle;
      white-space: nowrap;
    }

    /* Harmonize all checkboxes with the earthy color scheme */
    input[type="checkbox"] {
      accent-color: var(--color-kvot-accent);
    }

    #treeSearch {
      width: 100%;
      padding: 8px 32px 8px 12px;
      border: 1px solid var(--color-panel-border);
      border-radius: 4px;
      font-size: 13px;
      font-family: inherit;
      background: var(--color-panel-bg);
      color: var(--color-text-primary);
      transition: all 0.15s ease;
      outline: none;
    }

    #treeSearch:focus {
      border-color: var(--color-kvot-primary);
      box-shadow: 0 0 0 3px rgba(52, 65, 38, 0.1);
    }

    #treeSearch::placeholder {
      color: var(--color-text-muted);
    }

    .clear-search-btn {
      position: absolute;
      right: 8px;
      top: 50%;
      transform: translateY(-50%);
      background: none;
      border: none;
      color: var(--color-text-muted);
      font-size: 20px;
      line-height: 1;
      cursor: pointer;
      padding: 4px 8px;
      border-radius: 3px;
      transition: all 0.2s;
      display: none;
    }

    .clear-search-btn:hover {
      background: var(--color-hover-bg);
      color: var(--color-text-primary);
    }

    .clear-search-btn.visible {
      display: block;
    }

    /* Search Results Highlighting */
    .tree-item.search-hidden {
      display: none !important;
    }

    .tree-item.search-match {
      background: rgba(243, 184, 123, 0.15);
    }

    .tree-item.search-match .tree-label {
      font-weight: 600;
    }

    .search-highlight {
      background: var(--color-kvot-bright);
      color: var(--color-kvot-background);
      padding: 1px 2px;
      border-radius: 2px;
    }

    .tree-group-children.search-expanded {
      display: block !important;
    }

    /* ==========================================================================
       9. CHART & VISUALIZATION
       ========================================================================== */
    #plotlyChartContainer {
      position: relative;
      margin-bottom: 16px;
      display: none;
    }

    .plotly-loading {
      position: absolute;
      top: 50%;
      left: 50%;
      transform: translate(-50%, -50%);
      z-index: 10;
      background: rgba(255,255,255,0.8);
      padding: 16px 32px;
      border-radius: 8px;
      font-size: 1.2em;
      box-shadow: 0 2px 8px rgba(0,0,0,0.15);
      display: flex;
      align-items: center;
      gap: 12px;
    }
    [data-theme="dark"] .plotly-loading {
      background: rgba(42,34,27,0.85);
    }
    .plotly-loading .spinner {
      width: 24px;
      height: 24px;
      border: 4px solid #ccc;
      border-top: 4px solid #333;
      border-radius: 50%;
      animation: file-load-spin 0.9s linear infinite;
      display: inline-block;
    }
    [data-theme="dark"] .plotly-loading .spinner {
      border-color: rgba(255,255,255,0.15);
      border-top-color: var(--color-kvot-accent);
    }
    
    #plotlyChartContainer.visible {
      display: block;
    }
    
    #plotlyChart {
      /* adjustable minimum height; override via --plotly-chart-min-height */
      min-height: var(--plotly-chart-min-height, 200px);
      height: 500px;
      max-height: 2000px;
      overflow: hidden;
    }

    /* Vertical resize handle below the chart */
    .chart-resize-handle {
      height: 8px;
      cursor: row-resize;
      background: transparent;
      display: flex;
      align-items: center;
      justify-content: center;
      flex-shrink: 0;
    }
    .chart-resize-handle::after {
      content: '';
      height: 3px;
      width: 100%;
      border-radius: 0;
      background: transparent;
      transition: background 0.15s;
    }
    .chart-resize-handle:hover::after,
    .chart-resize-handle.active::after {
      background: var(--color-kvot-accent);
    }
    
    /* Chart Controls */
    .chart-controls {
      display: flex;
      gap: 12px;
      align-items: center;
      margin-bottom: 12px;
      padding: 12px;
      background: var(--color-hover-bg);
      border-radius: 6px;
      flex-wrap: wrap;
      border: 1px solid var(--color-panel-border);
    }
    
    .chart-controls label {
      display: flex;
      align-items: center;
      gap: 6px;
      font-size: 13px;
      color: var(--color-text-primary);
      font-weight: 500;
    }
    
    .chart-controls select {
      padding: 6px 24px 6px 10px;
      border: 1px solid var(--color-panel-border);
      border-radius: 4px;
      font-size: 13px;
      background: var(--color-panel-bg);
      color: var(--color-text-primary);
      cursor: pointer;
      appearance: none;
      background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%232d2416' d='M6 9L1 4h10z'/%3E%3C/svg%3E");
      background-repeat: no-repeat;
      background-position: right 8px center;
      background-size: 12px;
      transition: all 0.15s ease;
      outline: none;
    }
    
    .chart-controls select:hover {
      border-color: var(--color-kvot-accent);
      background-color: var(--color-panel-bg);
    }
    
    .chart-controls select:focus {
      border-color: var(--color-kvot-primary);
      box-shadow: 0 0 0 3px rgba(52, 65, 38, 0.1);
    }

    .chart-controls input[type="number"] {
      width: 54px;
      padding: 5px 6px;
      border: 1px solid var(--color-panel-border);
      border-radius: 4px;
      font-size: 13px;
      font-family: inherit;
      background: var(--color-panel-bg);
      color: var(--color-text-primary);
      outline: none;
      transition: all 0.15s ease;
      text-align: center;
    }

    .chart-controls input[type="number"]:hover {
      border-color: var(--color-kvot-accent);
    }

    .chart-controls input[type="number"]:focus {
      border-color: var(--color-kvot-primary);
      box-shadow: 0 0 0 3px rgba(52, 65, 38, 0.1);
    }

    /* Split pushbutton for axis scale selection */
    .chart-controls .scale-toggle {
      display: inline-flex;
      border: 1px solid var(--color-panel-border);
      border-radius: 999px; /* pill shape */
      /* no overflow hidden so the dividing line stays straight at corners */
      background: var(--color-panel-bg);
      cursor: pointer; /* entire area clickable */
      /* allow clicks even on button elements to bubble to container */
      user-select: none;
    }
    .chart-controls .scale-toggle button {
      flex: 1;
      padding: 3px 10px;
      border: none;
      background: transparent;
      color: var(--color-text-primary);
      cursor: default; /* container handles click */
      font-size: 12px;
      transition: background 0.15s ease, color 0.15s ease;
      position: relative;
      box-sizing: border-box;
    }
    .chart-controls .scale-toggle button:first-child {
      border-top-left-radius: 999px;
      border-bottom-left-radius: 999px;
      /* no border on the inner edge */
    }
    .chart-controls .scale-toggle button:last-child {
      border-top-right-radius: 999px;
      border-bottom-right-radius: 999px;
      border-left: none;
    }
    .chart-controls .scale-toggle button.active {
      background: var(--color-kvot-bright);
      color: var(--color-kvot-background);
    }
    .chart-controls .scale-toggle button:not(.active):hover {
      /* no background change on hover */
      background: transparent;
    }
    .chart-controls .scale-toggle button:focus {
      outline: none;
    }

    /* Disabled state for scale toggles and preset controls when axes are locked */
    .chart-controls .scale-toggle button:disabled,
    .chart-controls select:disabled,
    .chart-controls .preset-icon-btn:disabled {
      opacity: 0.35;
      pointer-events: none;
      cursor: not-allowed;
    }

    /* dark mode overrides – keep hover transparent */
    [data-theme="dark"] .chart-controls .scale-toggle button:not(.active):hover {
      background: transparent;
    }
    /* make unselected half text stand out but appear dimmer */
    [data-theme="dark"] .chart-controls .scale-toggle button:not(.active) {
      color: rgba(255,255,255,0.6); /* semi-transparent white */
      text-shadow: 0 0 1px rgba(0,0,0,0.5);
    }
    /* light mode dimmed text for inactive buttons */
    [data-theme="light"] .chart-controls .scale-toggle button:not(.active) {
      color: rgba(0,0,0,0.5);
    }
    
    .chart-controls button {
      padding: 6px 12px;
      background: var(--color-kvot-bright);
      color: var(--color-kvot-background);
      border: 1px solid var(--color-kvot-bright);
      border-radius: 4px;
      cursor: pointer;
      font-size: 13px;
      transition: all 0.2s;
      font-weight: 500;
    }
    
    .chart-controls button:hover {
      background: #f5c690;
      transform: translateY(-1px);
      box-shadow: 0 2px 4px rgba(53, 41, 33, 0.2);
    }
    /* scale-toggle buttons should not shift or shadow on hover */
    .chart-controls .scale-toggle button:hover {
      transform: none;
      box-shadow: none;
    }
    
    .chart-controls button.secondary {
      background: var(--color-text-secondary);
      color: white;
    }
    
    .chart-controls button.secondary:hover {
      background: var(--color-text-primary);
    }

    /* Preset icon buttons (＋ and ⚙) */
    .preset-icon-btn {
      padding: 4px 8px !important;
      font-size: 14px !important;
      line-height: 1;
      min-width: 28px;
    }

    /* Lock axes button */
    .lock-axes-btn {
      font-size: 12px !important;
      opacity: 0.6;
      transition: opacity 0.15s, background 0.15s, border-color 0.15s, box-shadow 0.15s;
      display: inline-flex !important;
      align-items: center;
      justify-content: center;
      border: 1.5px solid transparent;
    }
    .lock-axes-btn.active {
      opacity: 1;
      background: var(--color-accent, #8b6f47) !important;
      color: #fff !important;
      border-color: var(--color-accent, #8b6f47);
      box-shadow: 0 0 6px rgba(139, 111, 71, 0.5);
    }

    /* ---------- Preset Manager Overlay / Dialog ---------- */
    .preset-overlay {
      position: fixed;
      inset: 0;
      background: rgba(0,0,0,0.45);
      z-index: 9000;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .preset-dialog {
      background: var(--color-panel-bg);
      border: 1px solid var(--color-panel-border);
      border-radius: 8px;
      width: 460px;
      max-width: 90vw;
      box-shadow: 0 8px 24px rgba(0,0,0,0.25);
      overflow: hidden;
    }
    .preset-dialog-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 12px 16px;
      border-bottom: 1px solid var(--color-panel-border);
    }
    .preset-dialog-header h4 {
      margin: 0;
      font-size: 15px;
      color: var(--color-text-primary);
    }
    .preset-close-btn {
      background: none;
      border: none;
      font-size: 20px;
      cursor: pointer;
      color: var(--color-text-secondary);
      line-height: 1;
      padding: 0 4px;
    }
    .preset-close-btn:hover {
      color: var(--color-text-primary);
    }
    .preset-manager-list {
      padding: 8px 16px;
      max-height: 400px;
      overflow-y: auto;
    }
    .preset-manager-row {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 6px 0;
      border-bottom: 1px solid var(--color-hover-bg);
    }
    .preset-manager-row:last-child {
      border-bottom: none;
    }
    .preset-manager-name-block {
      flex: 1;
      min-width: 0;
      display: flex;
      flex-direction: column;
    }
    .preset-manager-name {
      font-size: 13px;
      color: var(--color-text-primary);
      overflow: hidden;
      text-overflow: ellipsis;
      white-space: nowrap;
    }
    .preset-manager-summary {
      font-size: 11px;
      color: var(--color-text-secondary);
      overflow: hidden;
      text-overflow: ellipsis;
      white-space: nowrap;
    }
    .preset-manager-actions {
      display: inline-flex;
      gap: 4px;
      flex-shrink: 0;
    }
    .preset-manager-actions button {
      padding: 3px 8px;
      font-size: 11px;
      border-radius: 3px;
      border: 1px solid var(--color-panel-border);
      background: var(--color-panel-bg);
      color: var(--color-text-primary);
      cursor: pointer;
      transition: background 0.15s;
    }
    .preset-manager-actions button:hover {
      background: var(--color-hover-bg);
    }
    .preset-manager-actions .preset-delete-btn {
      color: #c0392b;
      border-color: #c0392b;
    }
    .preset-manager-actions .preset-delete-btn:hover {
      background: #c0392b;
      color: #fff;
    }
    /* Inline edit form inside preset manager */
    .preset-edit-form {
      padding: 10px 0;
      border-bottom: 1px solid var(--color-hover-bg);
    }
    .preset-edit-row {
      display: flex;
      gap: 10px;
      align-items: center;
      margin-bottom: 6px;
      flex-wrap: wrap;
    }
    .preset-edit-row label {
      display: flex;
      align-items: center;
      gap: 4px;
      font-size: 12px;
      color: var(--color-text-primary);
      white-space: nowrap;
    }
    .preset-edit-row input[type="text"] {
      width: 80px;
      padding: 3px 6px;
      font-size: 12px;
      border: 1px solid var(--color-panel-border);
      border-radius: 3px;
      background: var(--color-panel-bg);
      color: var(--color-text-primary);
    }
    .preset-edit-row .preset-name-input {
      width: 220px;
    }
    .preset-edit-row select {
      padding: 3px 6px;
      font-size: 12px;
      border: 1px solid var(--color-panel-border);
      border-radius: 3px;
      background: var(--color-panel-bg);
      color: var(--color-text-primary);
    }
    .preset-edit-btns {
      display: flex;
      gap: 6px;
      margin-top: 6px;
    }
    .preset-edit-btns button {
      padding: 4px 12px;
      font-size: 12px;
      border-radius: 3px;
      border: 1px solid var(--color-panel-border);
      background: var(--color-panel-bg);
      color: var(--color-text-primary);
      cursor: pointer;
    }
    .preset-edit-btns button:hover {
      background: var(--color-hover-bg);
    }
    .preset-edit-save {
      background: var(--color-kvot-bright) !important;
      color: var(--color-kvot-background) !important;
      border-color: var(--color-kvot-bright) !important;
    }

    .preset-dialog-footer {
      display: flex;
      gap: 8px;
      padding: 12px 16px;
      border-top: 1px solid var(--color-panel-border);
    }
    .preset-dialog-footer button {
      padding: 6px 14px;
      font-size: 12px;
      border-radius: 4px;
      border: 1px solid var(--color-panel-border);
      background: var(--color-panel-bg);
      color: var(--color-text-primary);
      cursor: pointer;
      transition: background 0.15s;
    }
    .preset-dialog-footer button:hover {
      background: var(--color-hover-bg);
    }

    /* ==========================================================================
       10. DATASET INFO PANEL
       ========================================================================== */
    #info { 
      flex: 1;
    }

    /* Welcome / introduction panel */
    .welcome-panel {
      padding: 4px 0;
      line-height: 1.6;
    }
    .welcome-panel h2 {
      margin: 0 0 8px;
      font-size: 20px;
      font-weight: 700;
      color: var(--color-kvot-primary);
    }
    .welcome-panel > p {
      margin: 0 0 18px;
      color: var(--color-text-secondary);
      font-size: 13px;
    }
    .welcome-section {
      margin-bottom: 16px;
      padding: 12px 14px;
      background: var(--color-hover-bg);
      border-radius: 6px;
      border: 1px solid var(--color-panel-border);
    }
    .welcome-section h4 {
      margin: 0 0 8px;
      font-size: 13px;
      font-weight: 600;
      color: var(--color-kvot-accent);
    }
    .welcome-section ol,
    .welcome-section ul {
      margin: 0;
      padding-left: 20px;
    }
    .welcome-section li {
      margin-bottom: 5px;
      font-size: 12.5px;
      color: var(--color-text-secondary);
    }
    .welcome-section li:last-child {
      margin-bottom: 0;
    }
    .welcome-section code {
      background: var(--color-panel-border);
      padding: 1px 5px;
      border-radius: 3px;
      font-size: 11.5px;
      font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Fira Code', monospace;
    }
    .welcome-section kbd {
      display: inline-block;
      padding: 1px 6px;
      font-size: 11px;
      font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Fira Code', monospace;
      background: var(--color-panel-bg);
      border: 1px solid var(--color-panel-border);
      border-radius: 3px;
      box-shadow: 0 1px 0 var(--color-panel-border);
    }
    
    .info-section { 
      margin-bottom: 16px; 
    }
    
    .info-label { 
      font-weight: 600; 
      margin-bottom: 6px; 
      color: var(--color-kvot-primary); 
      font-size: 13px;
    }
    
    .info-content { 
      background: var(--color-hover-bg); 
      padding: 10px; 
      border-radius: 4px; 
      font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Fira Code', monospace; 
      font-size: 12px; 
      max-height: 300px; 
      overflow-y: auto; 
      word-break: break-all;
      color: var(--color-text-secondary);
      border: 1px solid var(--color-panel-border);
    }
    
    .file-data-section {
      margin-bottom: 12px;
      padding: 12px;
      background: var(--color-hover-bg);
      border-radius: 6px;
      border: 1px solid var(--color-panel-border);
      border-left: 3px solid var(--color-kvot-accent);
    }
    
    .file-data-section h4 {
      margin: 0 0 8px 0;
      color: var(--color-kvot-background);
      font-size: 13px;
      font-weight: 600;
    }

    .multi-select-hint {
      background: var(--color-kvot-bright);
      color: var(--color-kvot-background);
      padding: 8px 12px;
      border-radius: 4px;
      font-size: 12px;
      margin-bottom: 12px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .multi-select-hint .hint-close {
      margin-left: auto;
      width: 16px;
      height: 16px;
      border-radius: 3px;
      display: flex;
      align-items: center;
      justify-content: center;
      transition: background 0.2s;
      font-size: 14px;
      line-height: 1;
      cursor: pointer;
    }
    .multi-select-hint .hint-close:hover {
      background: rgba(0, 0, 0, 0.2);
    }
    [data-theme="dark"] .multi-select-hint .hint-close:hover {
      background: rgba(53, 41, 33, 0.15);
    }
    .show-hint-button {
      cursor: pointer;
      font-size: 14px;
      vertical-align: middle;
      opacity: 0.6;
      transition: opacity 0.15s;
    }
    .show-hint-button:hover {
      opacity: 1;
    }

    /* ==========================================================================
       11. STATUS & FEEDBACK STATES
       ========================================================================== */
    .error { 
      background: #fef2f2; 
      color: #991b1b; 
      padding: 12px; 
      border-radius: 4px; 
      margin-top: 12px;
      border: 1px solid #fecaca;
    }

    [data-theme="dark"] .error {
      background: #3b1515;
      color: #fca5a5;
      border-color: #7f1d1d;
    }
    
    .loading { 
      color: var(--color-text-muted); 
      font-style: italic; 
    }

    /* File load ticker shown next to file tabs while files/tree are being processed */
    .file-load-ticker {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      margin-left: 12px;
      font-size: 13px;
      color: var(--color-text-muted);
    }
    .file-load-ticker .spinner {
      width: 12px;
      height: 12px;
      border: 2px solid rgba(0,0,0,0.12);
      border-top-color: var(--color-kvot-accent);
      border-radius: 50%;
      animation: file-load-spin 0.9s linear infinite;
    }
    @keyframes file-load-spin { to { transform: rotate(360deg); } }
    [data-theme="dark"] .file-load-ticker .spinner { border: 2px solid rgba(255,255,255,0.12); }
    .file-load-ticker[hidden] { display: none !important; }

    /* small inline spinner used inside the tree for fast feedback */
    .tree-inline-spinner {
      width: 12px;
      height: 12px;
      border: 2px solid rgba(0,0,0,0.12);
      border-top-color: var(--color-kvot-accent);
      border-radius: 50%;
      animation: file-load-spin 0.9s linear infinite;
      display: inline-block;
      vertical-align: middle;
      margin-left: 6px;
    }

    /* determinate progress bar inside the ticker */

    /* File badges (small colored dots showing which files contain a node) */
    .tree-toggle.no-toggle { visibility: hidden; width: 12px; display: inline-block; }
    .file-load-ticker .ticker-progress { width: 160px; height: 6px; background: rgba(0,0,0,0.06); border-radius: 6px; overflow: hidden; }
    .file-load-ticker .ticker-progress-bar { height: 100%; width: 0%; background: var(--color-kvot-accent); transition: width 220ms linear; }

/* cancel button shown inside the inline file-load ticker for long tree recalculations */
.file-load-ticker .ticker-cancel {
  background: transparent;
  border: 0;
  color: var(--color-kvot-accent);
  font-size: 12px;
  cursor: pointer;
  padding: 2px 6px;
  border-radius: 4px;
  display: none;
}
.file-load-ticker .ticker-cancel:hover { background: rgba(0,0,0,0.06); }



    /* ==========================================================================
       12. DRAG & DROP SORTING (SortableJS)
       ========================================================================== */
    .sortable-ghost {
      opacity: 0.4;
    }
    
    .sortable-drag {
      opacity: 0.8;
    }

    /* ==========================================================================
       16. UTILITIES & HIDDEN ELEMENTS
       ========================================================================== */
    #fileInput {
      display: none;
    }

    /* ==========================================================================
       17. CUSTOM SCROLLBAR
       ========================================================================== */
    ::-webkit-scrollbar {
      width: 8px;
      height: 8px;
    }
    
    ::-webkit-scrollbar-track {
      background: var(--color-hover-bg);
      border-radius: 4px;
    }
    
    ::-webkit-scrollbar-thumb {
      background: var(--color-text-muted);
      border-radius: 4px;
    }
    
    ::-webkit-scrollbar-thumb:hover {
      background: var(--color-text-secondary);
    }

    /* ==========================================================================
       18. DARK MODE CONTRAST FIXES
       Elements that use --color-kvot-primary (#344126) or
       --color-kvot-background (#352921) as text colour are nearly invisible
       on dark surfaces. Override them with high-contrast earthy alternatives.
       ========================================================================== */
    [data-theme="dark"] .panel h3 {
      color: var(--color-kvot-bright);
    }

    [data-theme="dark"] .tree-item.group {
      color: #8aad6a;                  /* light olive green */
    }

    [data-theme="dark"] .tree-item.group:hover {
      color: #c5d8b4;                  /* pale green */
    }

    [data-theme="dark"] .tree-item.group.expanded {
      color: #c5d8b4;
    }

    [data-theme="dark"] .pdf-histogram-container {
      background: var(--bg-secondary, #2a221b);
      border-color: var(--color-border);
    }

    [data-theme="dark"] .link-badge {
      color: var(--color-kvot-bright);
    }
    [data-theme="dark"] .link-badge.broken {
      color: #ff7777;
    }
    [data-theme="dark"] .link-badge.external {
      color: var(--color-kvot-bright);
    }
    [data-theme="dark"] .link-badge.soft {
      color: #8aad6a;
    }
    [data-theme="dark"] .info-section.link-info.soft {
      border-left-color: #8aad6a;
    }

    [data-theme="dark"] .info-label {
      color: var(--color-kvot-bright);
    }

    [data-theme="dark"] .file-data-section h4 {
      color: var(--color-kvot-bright);
    }

    [data-theme="dark"] #dropOverlay .message {
      color: var(--color-kvot-bright);
    }

    [data-theme="dark"] .chart-controls select {
      background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23e8ddd0' d='M6 9L1 4h10z'/%3E%3C/svg%3E");
    }

    [data-theme="dark"] .chart-controls button {
      color: var(--color-kvot-background);
    }

    [data-theme="dark"] .chart-controls button.secondary {
      background: var(--color-text-muted);
      color: var(--text-primary);
    }

    [data-theme="dark"] .chart-controls button.secondary:hover {
      background: var(--color-text-secondary);
    }

    [data-theme="dark"] .multi-select-hint {
      color: var(--color-kvot-background);
    }

    [data-theme="dark"] #treeSearch:focus {
      box-shadow: 0 0 0 3px rgba(243, 184, 123, 0.15);
    }

    [data-theme="dark"] .chart-controls select:focus {
      box-shadow: 0 0 0 3px rgba(243, 184, 123, 0.15);
    }

    [data-theme="dark"] .search-highlight {
      background: var(--color-kvot-accent);
      color: #fff;
    }

    /* ==========================================================================
       19. ROOT NODE & ATTRIBUTES TABLE
       ========================================================================== */

    /* Root node in tree */
    .tree-item.root-node {
      font-weight: 600;
      color: var(--color-kvot-primary);
      margin-bottom: 8px;
    }

    [data-theme="dark"] .tree-item.root-node {
      color: #8aad6a;
    }

    [data-theme="dark"] .tree-item.root-node:hover,
    [data-theme="dark"] .tree-item.root-node.expanded {
      color: #c5d8b4;
    }

    /* Attributes table */
    .attrs-table {
      width: 100%;
      border-collapse: separate;
      border-spacing: 12px 0;
      font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Fira Code', monospace;
      font-size: 11px;
      color: var(--color-text-primary);
    }

    .attrs-header {
      border-bottom: 1px solid var(--color-panel-border);
      background: var(--color-hover-bg);
    }

    .attrs-header th {
      text-align: left;
      padding: 6px 0;
      font-weight: 600;
      color: var(--color-text-primary);
      border-bottom: 1px solid var(--color-panel-border);
    }

    .attrs-header th:first-child {
      width: 1%;
      white-space: nowrap;
    }

    .attrs-row {
      border-bottom: 1px solid var(--color-panel-border);
    }

    .attrs-row td {
      padding: 6px 0;
      word-break: break-word;
      border-bottom: 1px solid var(--color-panel-border);
    }

    .attrs-row td:first-child {
      white-space: nowrap;
    }

    .attrs-value {
      color: var(--color-text-secondary);
    }

    /* Formatted JSON inside attribute values */
    .attrs-json {
      margin: 0;
      padding: 6px 8px;
      background: var(--color-hover-bg, #f5f5f5);
      border: 1px solid var(--color-panel-border, #ddd);
      border-radius: 4px;
      font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Fira Code', monospace;
      font-size: 11px;
      white-space: pre-wrap;
      word-break: break-word;
      max-height: 300px;
      overflow-y: auto;
    }

    /* Rendered HTML inside attribute values */
    .attrs-html {
      padding: 6px 8px;
      background: var(--color-hover-bg, #f5f5f5);
      border: 1px solid var(--color-panel-border, #ddd);
      border-radius: 4px;
      font-family: inherit;
      font-size: 12px;
      line-height: 1.5;
      max-height: 300px;
      overflow-y: auto;
    }

    /* Info panel action buttons (Download CSV / Download Excel) */
    .info-btn-csv {
      padding: 4px 8px;
      background: var(--color-kvot-background);
      color: var(--color-kvot-bright);
      border: none;
      border-radius: 3px;
      cursor: pointer;
      font-size: 11px;
      font-weight: 500;
      transition: background 0.2s;
    }
    .info-btn-csv:hover { background: var(--color-kvot-primary); }

    .info-btn-excel {
      padding: 6px 12px;
      background: #217346;
      color: white;
      border: none;
      border-radius: 4px;
      cursor: pointer;
      font-size: 12px;
      font-weight: 500;
      transition: background 0.2s;
    }
    .info-btn-excel:hover { background: #1e6b3f; }

    .info-multi-header {
      background: var(--color-kvot-bright);
      padding: 12px;
      border-radius: 6px;
      margin-bottom: 16px;
      font-weight: 600;
      color: var(--color-kvot-background);
    }

    .info-excel-footer {
      margin-top: 12px;
      padding-top: 12px;
      border-top: 1px solid var(--color-border);
    }