BookStack Code Mirror - hacks/blob - content/mermaid-viewer/head.html

   1 <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.7.2/css/all.min.css"
   2     integrity="sha512-Evv84Mr4kqVGRNSgIGL/F/aIDqQb7xQ2vcrdIwxfjThSH8CSR7PBEakCr51Ck+w+/U6swU2Im1vVX0SVk9ABhg=="
   3     crossorigin="anonymous" referrerpolicy="no-referrer" />
   4
   5 <script src="https://cdnjs.cloudflare.com/ajax/libs/mermaid/11.7.0/mermaid.min.js"
   6     integrity="sha512-ecc+vlmmc1f51s2l/AeIC552wULnv9Q8bYJ4FbODxsL6jGrFoLaKnGkN5JUZNH6LBjkAYy9Q4fKqyTuFUIvvFA=="
   7     crossorigin="anonymous" referrerpolicy="no-referrer"></script>
   8 <script type="module">
   9     // Detect if BookStack's dark mode is enabled
  10     const isDarkMode = document.documentElement.classList.contains('dark-mode');
  11
  12     // Initialize Mermaid.js, dynamically setting the theme based on BookStack's mode
  13     mermaid.initialize({
  14         startOnLoad: false,
  15         securityLevel: 'loose',
  16         theme: isDarkMode ? 'dark' : 'default'
  17     });
  18
  19     // Zoom Level Configuration
  20     const ZOOM_LEVEL_MIN = 0.5;
  21     const ZOOM_LEVEL_MAX = 2.0;
  22     const ZOOM_LEVEL_INCREMENT = 0.1;
  23     const DEFAULT_ZOOM_SCALE = 1.0;
  24
  25     const DRAG_THRESHOLD_PIXELS = 3;
  26     const ZOOM_ANIMATION_CLASS_TIMEOUT_MS = 200;
  27
  28     const CSS_CLASSES = {
  29         CONTAINER: 'mermaid-container',
  30         VIEWPORT: 'mermaid-viewport',
  31         CONTENT: 'mermaid-content',
  32         DIAGRAM: 'mermaid-diagram',
  33         CONTROLS: 'mermaid-controls',
  34         ZOOM_CONTROLS: 'mermaid-zoom-controls',
  35         INTERACTION_ENABLED: 'interaction-enabled',
  36         DRAGGING: 'dragging',
  37         ZOOMING: 'zooming',
  38         LOCK_ICON: 'fa fa-lock',
  39         UNLOCK_ICON: 'fa fa-unlock',
  40         INTERACTIVE_HOVER: 'interactive-hover', // Class for 'grab' cursor state
  41         INTERACTIVE_PAN: 'interactive-pan',     // Class for 'grabbing' cursor state
  42         BUTTON_BASE: 'mermaid-viewer-button-base' // Base class for all viewer buttons
  43     };
  44
  45     class InteractiveMermaidViewer {
  46         constructor(container, mermaidCode) {
  47             this.container = container;
  48             this.mermaidCode = mermaidCode;
  49             this.scale = 1.0;
  50             this.translateX = 0;
  51             this.translateY = 0;
  52             this.isDragging = false;
  53             this.dragStarted = false;
  54             this.startX = 0;
  55             this.startY = 0;
  56
  57             const numDecimalPlaces = (ZOOM_LEVEL_INCREMENT.toString().split('.')[1] || '').length;
  58             this.zoomLevels = Array.from(
  59                 { length: Math.round((ZOOM_LEVEL_MAX - ZOOM_LEVEL_MIN) / ZOOM_LEVEL_INCREMENT) + 1 },
  60                 (_, i) => parseFloat((ZOOM_LEVEL_MIN + i * ZOOM_LEVEL_INCREMENT).toFixed(numDecimalPlaces))
  61             );
  62
  63             this.currentZoomIndex = this.zoomLevels.findIndex(level => Math.abs(level - DEFAULT_ZOOM_SCALE) < 1e-9);
  64             if (this.currentZoomIndex === -1) {
  65                 this.currentZoomIndex = Math.floor(this.zoomLevels.length / 2);
  66             }
  67             this.interactionEnabled = false;
  68             this.initialContentOffset = { x: 0, y: 0 };
  69
  70             // Cache DOM elements
  71             this.toggleInteractionBtn = null;
  72             this.copyCodeBtn = null;
  73             this.zoomInBtn = null;
  74             this.zoomOutBtn = null;
  75             this.zoomResetBtn = null;
  76
  77             // Bind event handlers for proper addition and removal
  78             this.boundMouseMoveHandler = this.handleMouseMove.bind(this);
  79             this.boundMouseUpHandler = this.handleMouseUp.bind(this);
  80             this.boundToggleInteraction = this.toggleInteraction.bind(this);
  81             this.boundCopyCode = this.copyCode.bind(this);
  82             this.boundZoomIn = this.handleZoomClick.bind(this, 1);
  83             this.boundZoomOut = this.handleZoomClick.bind(this, -1);
  84             this.boundResetZoom = this.resetZoom.bind(this);
  85             this.boundHandleWheel = this.handleWheel.bind(this);
  86             this.boundHandleMouseDown = this.handleMouseDown.bind(this);
  87             this.boundPreventDefault = e => e.preventDefault();
  88             this.boundPreventSelect = e => { if (this.isDragging || this.interactionEnabled) e.preventDefault(); };
  89
  90             this.setupViewer();
  91             this.setupEventListeners();
  92         }
  93
  94         /**
  95          * Creates the DOM structure for the viewer programmatically.
  96          * This is safer and more maintainable than using innerHTML with a large template string.
  97          */
  98         setupViewer() {
  99             const createButton = (title, iconClass, ...extraClasses) => {
 100                 const button = document.createElement('div');
 101                 button.className = `${CSS_CLASSES.BUTTON_BASE} ${extraClasses.join(' ')}`;
 102                 button.title = title;
 103                 const icon = document.createElement('i');
 104                 icon.className = iconClass;
 105                 icon.setAttribute('aria-hidden', 'true');
 106                 button.append(icon);
 107                 return button;
 108             };
 109
 110             const controls = document.createElement('div');
 111             controls.className = CSS_CLASSES.CONTROLS;
 112             this.toggleInteractionBtn = createButton('Toggle interaction', CSS_CLASSES.LOCK_ICON, 'mermaid-btn', 'toggle-interaction');
 113             this.copyCodeBtn = createButton('Copy code', 'fa fa-copy', 'mermaid-btn');
 114             controls.append(this.toggleInteractionBtn, this.copyCodeBtn);
 115
 116             const zoomControls = document.createElement('div');
 117             zoomControls.className = CSS_CLASSES.ZOOM_CONTROLS;
 118             this.zoomInBtn = createButton('Zoom in', 'fa fa-search-plus', 'mermaid-zoom-btn', 'zoom-in');
 119             this.zoomOutBtn = createButton('Zoom out', 'fa fa-search-minus', 'mermaid-zoom-btn', 'zoom-out');
 120             this.zoomResetBtn = createButton('Reset', 'fa fa-refresh', 'mermaid-zoom-btn', 'zoom-reset');
 121             zoomControls.append(this.zoomInBtn, this.zoomOutBtn, this.zoomResetBtn);
 122
 123             this.diagram = document.createElement('div');
 124             this.diagram.className = CSS_CLASSES.DIAGRAM;
 125             // Use textContent for security, preventing any potential HTML injection.
 126             // Mermaid will parse the text content safely.
 127             this.diagram.textContent = this.mermaidCode;
 128
 129             this.content = document.createElement('div');
 130             this.content.className = CSS_CLASSES.CONTENT;
 131             this.content.append(this.diagram);
 132
 133             this.viewport = document.createElement('div');
 134             this.viewport.className = CSS_CLASSES.VIEWPORT;
 135             this.viewport.append(this.content);
 136
 137             // Clear the container and append the new structure
 138             this.container.innerHTML = '';
 139             this.container.append(controls, zoomControls, this.viewport);
 140
 141             // Function to render the diagram and perform post-render setup
 142             const renderAndSetup = () => {
 143                 mermaid.run({ nodes: [this.diagram] }).then(() => {
 144                     this.adjustContainerHeight();
 145                     this.calculateInitialOffset();
 146                     this.centerDiagram();
 147                 }).catch(error => {
 148                     console.error("Mermaid rendering error for diagram:", this.mermaidCode, error);
 149                     this.diagram.innerHTML = `<p style="color: red; padding: 10px;">Error rendering diagram. Check console.</p>`;
 150                 });
 151             };
 152
 153             // Check if Font Awesome is loaded before rendering
 154             // This checks for the 'Font Awesome 6 Free' font family, which is common.
 155             // Adjust if your Font Awesome version uses a different family name for its core icons.
 156             if (document.fonts && typeof document.fonts.check === 'function' && document.fonts.check('1em "Font Awesome 6 Free"')) { // Check if Font Awesome is immediately available
 157                 renderAndSetup();
 158             } else if (document.fonts && document.fonts.ready) { // Simplified check for document.fonts.ready
 159                 document.fonts.ready.then(renderAndSetup).catch(err => {
 160                     renderAndSetup(); // Proceed with rendering even if font check fails after timeout/error
 161                 });
 162             } else {
 163                 renderAndSetup();
 164             }
 165         }
 166
 167         adjustContainerHeight() {
 168             const svgElement = this.content.querySelector('svg');
 169             if (svgElement) {
 170                 // Ensure the viewport takes up the height of the rendered SVG
 171                 this.viewport.style.height = '100%';
 172             }
 173         }
 174
 175         calculateInitialOffset() {
 176             const originalTransform = this.content.style.transform;
 177             this.content.style.transform = '';
 178             const contentRect = this.content.getBoundingClientRect();
 179             const viewportRect = this.viewport.getBoundingClientRect();
 180             this.initialContentOffset.x = contentRect.left - viewportRect.left;
 181             this.initialContentOffset.y = contentRect.top - viewportRect.top;
 182             this.content.style.transform = originalTransform;
 183         }
 184
 185         _getViewportCenterClientCoords() {
 186             const viewportRect = this.viewport.getBoundingClientRect();
 187             return {
 188                 clientX: viewportRect.left + viewportRect.width / 2,
 189                 clientY: viewportRect.top + viewportRect.height / 2,
 190             };
 191         }
 192
 193         setupEventListeners() {
 194             this.toggleInteractionBtn.addEventListener('click', this.boundToggleInteraction);
 195             this.copyCodeBtn.addEventListener('click', this.boundCopyCode);
 196             this.zoomInBtn.addEventListener('click', this.boundZoomIn);
 197             this.zoomOutBtn.addEventListener('click', this.boundZoomOut);
 198             this.zoomResetBtn.addEventListener('click', this.boundResetZoom);
 199
 200             this.viewport.addEventListener('wheel', this.boundHandleWheel, { passive: false });
 201             this.viewport.addEventListener('mousedown', this.boundHandleMouseDown);
 202
 203             // Listen on document for mousemove to handle dragging outside viewport
 204             document.addEventListener('mousemove', this.boundMouseMoveHandler);
 205             // Listen on window for mouseup to ensure drag ends even if mouse is released outside
 206             window.addEventListener('mouseup', this.boundMouseUpHandler, true); // Use capture phase
 207
 208             this.viewport.addEventListener('contextmenu', this.boundPreventDefault);
 209             this.viewport.addEventListener('selectstart', this.boundPreventSelect);
 210         }
 211
 212         toggleInteraction() {
 213             this.interactionEnabled = !this.interactionEnabled;
 214             const icon = this.toggleInteractionBtn.querySelector('i');
 215             this.toggleInteractionBtn.setAttribute('aria-pressed', this.interactionEnabled.toString());
 216
 217             if (this.interactionEnabled) {
 218                 icon.className = CSS_CLASSES.UNLOCK_ICON;
 219                 this.toggleInteractionBtn.title = 'Disable manual interaction';
 220                 this.viewport.classList.add(CSS_CLASSES.INTERACTION_ENABLED);
 221                 this.viewport.classList.add(CSS_CLASSES.INTERACTIVE_HOVER); // Set grab cursor state
 222                 this.viewport.classList.remove(CSS_CLASSES.INTERACTIVE_PAN); // Ensure pan cursor state is off
 223             } else {
 224                 icon.className = CSS_CLASSES.LOCK_ICON;
 225                 this.toggleInteractionBtn.title = 'Enable manual interaction';
 226                 this.viewport.classList.remove(CSS_CLASSES.INTERACTION_ENABLED);
 227                 this.viewport.classList.remove(CSS_CLASSES.INTERACTIVE_HOVER);
 228                 this.viewport.classList.remove(CSS_CLASSES.INTERACTIVE_PAN);
 229                 this.isDragging = false; // Ensure dragging stops if interaction is disabled mid-drag
 230                 this.dragStarted = false;
 231                 this.viewport.classList.remove(CSS_CLASSES.DRAGGING);
 232             }
 233         }
 234
 235         updateTransform() {
 236             this.content.style.transform = `translate(${this.translateX}px, ${this.translateY}px) scale(${this.scale})`;
 237         }
 238
 239         handleZoomClick(direction) {
 240             const { clientX, clientY } = this._getViewportCenterClientCoords();
 241             this.zoom(direction, clientX, clientY);
 242         }
 243
 244         handleWheel(e) {
 245             if (!this.interactionEnabled) return;
 246             // Prevent default browser scroll/zoom behavior when wheeling over the diagram
 247             e.preventDefault();
 248             this.content.classList.add(CSS_CLASSES.ZOOMING);
 249             const clientX = e.clientX;
 250             const clientY = e.clientY;
 251             if (e.deltaY > 0) this.zoom(-1, clientX, clientY);
 252             else this.zoom(1, clientX, clientY);
 253             setTimeout(() => this.content.classList.remove(CSS_CLASSES.ZOOMING), ZOOM_ANIMATION_CLASS_TIMEOUT_MS);
 254         }
 255
 256         handleMouseDown(e) {
 257             if (!this.interactionEnabled || e.button !== 0) return;
 258             e.preventDefault();
 259             this.isDragging = true;
 260             this.dragStarted = false;
 261             this.startX = e.clientX;
 262             this.startY = e.clientY;
 263             this.dragBaseTranslateX = this.translateX;
 264             this.dragBaseTranslateY = this.translateY;
 265             this.viewport.classList.add(CSS_CLASSES.DRAGGING);
 266             this.viewport.classList.remove(CSS_CLASSES.INTERACTIVE_HOVER);
 267             this.viewport.classList.add(CSS_CLASSES.INTERACTIVE_PAN);
 268             this.content.classList.remove(CSS_CLASSES.ZOOMING);
 269         }
 270
 271         handleMouseMove(e) {
 272             if (!this.isDragging) return;
 273             // e.preventDefault() is called only after dragStarted is true to allow clicks if threshold isn't met.
 274             const deltaX = e.clientX - this.startX;
 275             const deltaY = e.clientY - this.startY;
 276             if (!this.dragStarted && (Math.abs(deltaX) > DRAG_THRESHOLD_PIXELS || Math.abs(deltaY) > DRAG_THRESHOLD_PIXELS)) {
 277                 this.dragStarted = true;
 278             }
 279             if (this.dragStarted) {
 280                 e.preventDefault(); // Prevent text selection, etc., only when drag has truly started
 281                 this.translateX = this.dragBaseTranslateX + deltaX;
 282                 this.translateY = this.dragBaseTranslateY + deltaY;
 283                 this.updateTransform();
 284             }
 285         }
 286
 287         handleMouseUp() {
 288             if (this.isDragging) {
 289                 this.isDragging = false;
 290                 this.dragStarted = false;
 291                 this.viewport.classList.remove(CSS_CLASSES.DRAGGING);
 292                 this.viewport.classList.remove(CSS_CLASSES.INTERACTIVE_PAN);
 293                 if (this.interactionEnabled) { // Revert to grab cursor if interaction is still enabled
 294                     this.viewport.classList.add(CSS_CLASSES.INTERACTIVE_HOVER);
 295                 }
 296             }
 297             this.content.style.transform = `translate(${this.translateX}px, ${this.translateY}px) scale(${this.scale})`;
 298         }
 299
 300         centerDiagram() {
 301             const svgElement = this.content.querySelector('svg');
 302             if (svgElement) {
 303                 const viewportRect = this.viewport.getBoundingClientRect();
 304                 const svgIntrinsicWidth = svgElement.viewBox.baseVal.width || svgElement.clientWidth;
 305                 const svgIntrinsicHeight = svgElement.viewBox.baseVal.height || svgElement.clientHeight;
 306
 307                 const targetContentLeftRelativeToViewport = (viewportRect.width - (svgIntrinsicWidth * this.scale)) / 2;
 308                 const targetContentTopRelativeToViewport = (viewportRect.height - (svgIntrinsicHeight * this.scale)) / 2;
 309
 310                 this.translateX = targetContentLeftRelativeToViewport - this.initialContentOffset.x;
 311                 this.translateY = targetContentTopRelativeToViewport - this.initialContentOffset.y;
 312
 313                 // Initial centering constraints; may need adjustment for very large diagrams.
 314                 this.translateX = Math.max(0, this.translateX);
 315                 this.translateY = Math.max(0, this.translateY);
 316
 317                 this.updateTransform();
 318             }
 319         }
 320
 321         zoom(direction, clientX, clientY) {
 322             this.content.classList.add(CSS_CLASSES.ZOOMING);
 323             const oldScale = this.scale;
 324             let newZoomIndex = this.currentZoomIndex + direction;
 325
 326             if (newZoomIndex >= 0 && newZoomIndex < this.zoomLevels.length) {
 327                 this.currentZoomIndex = newZoomIndex;
 328                 const newScale = this.zoomLevels[this.currentZoomIndex];
 329
 330                 const viewportRect = this.viewport.getBoundingClientRect();
 331                 const pointXInContent = (clientX - viewportRect.left - this.translateX) / oldScale;
 332                 const pointYInContent = (clientY - viewportRect.top - this.translateY) / oldScale;
 333
 334                 this.translateX = (clientX - viewportRect.left) - (pointXInContent * newScale);
 335                 this.translateY = (clientY - viewportRect.top) - (pointYInContent * newScale);
 336                 this.scale = newScale;
 337                 this.updateTransform();
 338             }
 339             setTimeout(() => this.content.classList.remove(CSS_CLASSES.ZOOMING), ZOOM_ANIMATION_CLASS_TIMEOUT_MS);
 340         }
 341
 342         resetZoom() {
 343             this.content.classList.add(CSS_CLASSES.ZOOMING);
 344             this.currentZoomIndex = this.zoomLevels.findIndex(level => Math.abs(level - DEFAULT_ZOOM_SCALE) < 1e-9);
 345             if (this.currentZoomIndex === -1) { // Fallback if default not exactly in levels
 346                 this.currentZoomIndex = Math.floor(this.zoomLevels.length / 2);
 347             }
 348             this.scale = this.zoomLevels[this.currentZoomIndex];
 349             // Use requestAnimationFrame to ensure layout is stable before centering
 350             requestAnimationFrame(() => {
 351                 this.centerDiagram();
 352                 setTimeout(() => this.content.classList.remove(CSS_CLASSES.ZOOMING), ZOOM_ANIMATION_CLASS_TIMEOUT_MS);
 353             });
 354         }
 355
 356         async copyCode() {
 357             try {
 358                 await navigator.clipboard.writeText(this.mermaidCode);
 359                 this.showNotification('Copied!');
 360             } catch (_error) {
 361                 // Fallback for older browsers or if clipboard API fails
 362                 const textArea = document.createElement('textarea');
 363                 textArea.value = this.mermaidCode;
 364                 // Style to make it invisible
 365                 textArea.style.position = 'fixed';
 366                 textArea.style.top = '-9999px';
 367                 textArea.style.left = '-9999px';
 368                 document.body.appendChild(textArea);
 369                 textArea.select();
 370                 try {
 371                     document.execCommand('copy');
 372                     this.showNotification('Copied!');
 373                 } catch (copyError) {
 374                     console.error('Fallback copy failed:', copyError);
 375                     this.showNotification('Copy failed.', true); // Error
 376                 }
 377                 document.body.removeChild(textArea);
 378             }
 379         }
 380
 381         showNotification(message, isError = false) {
 382             if (window.$events) {
 383                 const eventName = isError ? 'error' : 'success';
 384                 window.$events.emit(eventName, message);
 385             } else {
 386                 // Fallback for if the event system is not available
 387                 console.warn('BookStack event system not found, falling back to console log for notification.');
 388                 if (isError) {
 389                     console.error(message);
 390                 } else {
 391                     console.log(message);
 392                 }
 393             }
 394         }
 395
 396         destroy() {
 397             // Remove event listeners specific to this instance
 398             this.toggleInteractionBtn.removeEventListener('click', this.boundToggleInteraction);
 399             this.copyCodeBtn.removeEventListener('click', this.boundCopyCode);
 400             this.zoomInBtn.removeEventListener('click', this.boundZoomIn);
 401             this.zoomOutBtn.removeEventListener('click', this.boundZoomOut);
 402             this.zoomResetBtn.removeEventListener('click', this.boundResetZoom);
 403
 404             this.viewport.removeEventListener('wheel', this.boundHandleWheel, { passive: false });
 405             this.viewport.removeEventListener('mousedown', this.boundHandleMouseDown);
 406             this.viewport.removeEventListener('contextmenu', this.boundPreventDefault);
 407             this.viewport.removeEventListener('selectstart', this.boundPreventSelect);
 408
 409             document.removeEventListener('mousemove', this.boundMouseMoveHandler);
 410             window.removeEventListener('mouseup', this.boundMouseUpHandler, true);
 411
 412             this.container.innerHTML = ''; // Clear the container's content
 413         }
 414     }
 415
 416     const mermaidViewers = [];
 417     function initializeMermaidViewers() {
 418         // Adjust the selector if your CMS wraps mermaid code blocks differently
 419         const codeBlocks = document.querySelectorAll('pre code.language-mermaid');
 420         for (const codeBlock of codeBlocks) {
 421             // Ensure we don't re-initialize if this script runs multiple times or content is dynamic
 422             if (codeBlock.dataset.mermaidViewerInitialized) continue;
 423
 424             const mermaidCode = codeBlock.textContent || codeBlock.innerHTML; // textContent is usually better
 425             const container = document.createElement('div');
 426             container.className = CSS_CLASSES.CONTAINER;
 427
 428             const replaceTarget = (codeBlock.nodeName === 'CODE') ? codeBlock.parentElement : codeBlock;
 429
 430             // Check if replaceTarget is already a mermaid-container (e.g. from previous init)
 431             if (replaceTarget.classList.contains(CSS_CLASSES.CONTAINER)) continue;
 432
 433             replaceTarget.after(container);
 434             replaceTarget.remove(); // Remove the original <pre> or <pre><code> block
 435
 436             const viewer = new InteractiveMermaidViewer(container, mermaidCode);
 437             mermaidViewers.push(viewer);
 438             codeBlock.dataset.mermaidViewerInitialized = 'true'; // Mark as initialized
 439         }
 440     }
 441
 442     // Initialize on DOMContentLoaded
 443     if (document.readyState === 'loading') {
 444         document.addEventListener('DOMContentLoaded', initializeMermaidViewers);
 445     } else {
 446         // DOMContentLoaded has already fired
 447         initializeMermaidViewers();
 448     }
 449
 450     // Re-center diagrams on window load, as images/fonts inside SVG might affect size
 451     window.addEventListener('load', () => {
 452         mermaidViewers.forEach(viewer => {
 453             // Delay slightly to ensure mermaid rendering is fully complete and dimensions are stable
 454             setTimeout(() => viewer.centerDiagram(), 100);
 455         });
 456     });
 457
 458     // Optional: If your CMS dynamically adds content, you might need a way to re-run initialization
 459     // For example, using a MutationObserver or a custom event.
 460     // document.addEventListener('myCMSContentLoaded', () => initializeMermaidViewers());
 461
 462 </script>
 463 <style>
 464     /* Use BookStack's CSS variables for seamless theme integration */
 465     .mermaid-container {
 466         background: var(--color-bg-alt);
 467         border: 1px solid #d0d7de;
 468         border-radius: 6px;
 469         position: relative;
 470         margin: 20px 0;
 471     }
 472
 473     .mermaid-viewport {
 474         height: 100%;
 475         /* This will now be 100% of the dynamically set container height */
 476         overflow: hidden;
 477         /* Keep this for panning/zooming when content exceeds viewport */
 478         cursor: auto;
 479         /* Default to normal system cursor */
 480     }
 481
 482     /* Ensure viewport cursor is auto when locked, even if active.
 483            The text selection (I-beam) cursor will still appear over selectable text within .mermaid-content. */
 484     .mermaid-viewport:not(.interaction-enabled):active {
 485         cursor: auto;
 486     }
 487
 488     /* Set 'grab' cursor when the viewport has the 'interactive-hover' class. */
 489     .mermaid-viewport.interactive-hover {
 490         cursor: grab;
 491     }
 492
 493     /* Set 'grabbing' cursor when the viewport has the 'interactive-pan' class. */
 494     .mermaid-viewport.interactive-pan {
 495         cursor: grabbing !important;
 496     }
 497
 498     .mermaid-content {
 499         transform-origin: 0 0;
 500         /* Allow text selection by default (when interaction is locked) */
 501         user-select: auto;
 502         /* or 'text' */
 503         will-change: transform;
 504     }
 505
 506     /* Disable text selection ONLY when interaction is enabled on the viewport */
 507     .mermaid-viewport.interaction-enabled .mermaid-content {
 508         user-select: none;
 509     }
 510
 511     /* SVG elements inherit cursor from the viewport when interaction is enabled. */
 512     .mermaid-viewport.interaction-enabled .mermaid-content svg,
 513     .mermaid-viewport.interaction-enabled .mermaid-content svg * {
 514         cursor: inherit !important;
 515         /* Force inheritance from the viewport's cursor */
 516     }
 517
 518     .mermaid-content.zooming {
 519         transition: transform 0.2s ease;
 520     }
 521
 522     .mermaid-controls {
 523         position: absolute;
 524         top: 10px;
 525         right: 10px;
 526         display: flex;
 527         gap: 5px;
 528         z-index: 10;
 529     }
 530
 531     .mermaid-viewer-button-base {
 532         border: 1px solid #d0d7de;
 533         border-radius: 6px;
 534         cursor: pointer;
 535         display: flex;
 536         align-items: center;
 537         justify-content: center;
 538         user-select: none;
 539         background: var(--color-bg);
 540         width: 32px;
 541         height: 32px;
 542         color: var(--color-text);
 543     }
 544
 545     .mermaid-viewer-button-base:hover {
 546         background: #f6f8fa;
 547     }
 548
 549     .dark-mode .mermaid-viewer-button-base:hover {
 550         background: var(--color-bg-alt);
 551     }
 552
 553     /* Override for pure white icons in dark mode */
 554     .dark-mode .mermaid-viewer-button-base {
 555         color: #fff;
 556     }
 557
 558     .mermaid-zoom-controls {
 559         position: absolute;
 560         bottom: 10px;
 561         left: 10px;
 562         display: flex;
 563         flex-direction: column;
 564         gap: 5px;
 565         z-index: 10;
 566     }
 567 </style>