diff --git a/docs/config/setup/interfaces/mermaid.RenderResult.md b/docs/config/setup/interfaces/mermaid.RenderResult.md
index f4960e6d0..6fd67a2ac 100644
--- a/docs/config/setup/interfaces/mermaid.RenderResult.md
+++ b/docs/config/setup/interfaces/mermaid.RenderResult.md
@@ -39,7 +39,7 @@ bindFunctions?.(div); // To call bindFunctions only if it's present.
 
 #### Defined in
 
-[packages/mermaid/src/types.ts:100](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L100)
+[packages/mermaid/src/types.ts:105](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L105)
 
 ---
 
@@ -51,7 +51,7 @@ The diagram type, e.g. 'flowchart', 'sequence', etc.
 
 #### Defined in
 
-[packages/mermaid/src/types.ts:90](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L90)
+[packages/mermaid/src/types.ts:95](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L95)
 
 ---
 
@@ -63,4 +63,4 @@ The svg code for the rendered graph.
 
 #### Defined in
 
-[packages/mermaid/src/types.ts:86](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L86)
+[packages/mermaid/src/types.ts:91](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/types.ts#L91)
diff --git a/packages/mermaid-layout-elk/src/render.ts b/packages/mermaid-layout-elk/src/render.ts
index 39ad5dcda..9ddd81780 100644
--- a/packages/mermaid-layout-elk/src/render.ts
+++ b/packages/mermaid-layout-elk/src/render.ts
@@ -10,6 +10,21 @@ import { curveLinear } from 'd3';
 import ELK from 'elkjs/lib/elk.bundled.js';
 import { type TreeData, findCommonAncestor } from './find-common-ancestor.js';
 
+type Node = LayoutData['nodes'][number];
+
+interface LabelData {
+  width: number;
+  height: number;
+  wrappingWidth?: number;
+  labelNode?: SVGGElement | null;
+}
+
+interface NodeWithVertex extends Omit<Node, 'domId'> {
+  children?: unknown[];
+  labelData?: LabelData;
+  domId?: Node['domId'] | SVGGroup | d3.Selection<SVGAElement, unknown, Element | null, unknown>;
+}
+
 export const render = async (
   data4Layout: LayoutData,
   svg: SVG,
@@ -31,27 +46,37 @@ export const render = async (
   const nodeDb: Record<string, any> = {};
   const clusterDb: Record<string, any> = {};
 
-  const addVertex = async (nodeEl: any, graph: { children: any[] }, nodeArr: any, node: any) => {
-    const labelData: any = { width: 0, height: 0 };
+  const addVertex = async (
+    nodeEl: SVGGroup,
+    graph: { children: NodeWithVertex[] },
+    nodeArr: Node[],
+    node: Node
+  ) => {
+    const labelData: LabelData = { width: 0, height: 0 };
 
-    let boundingBox;
-    const child = {
-      ...node,
-    };
-    graph.children.push(child);
-    nodeDb[node.id] = child;
     const config = getConfig();
 
     // Add the element to the DOM
     if (!node.isGroup) {
+      const child: NodeWithVertex = {
+        ...node,
+      };
+      graph.children.push(child);
+      nodeDb[node.id] = child;
+
       const childNodeEl = await insertNode(nodeEl, node, { config, dir: node.dir });
-      boundingBox = childNodeEl.node().getBBox();
+      const boundingBox = childNodeEl.node()!.getBBox();
       child.domId = childNodeEl;
       child.width = boundingBox.width;
       child.height = boundingBox.height;
     } else {
       // A subgraph
-      child.children = [];
+      const child: NodeWithVertex & { children: NodeWithVertex[] } = {
+        ...node,
+        children: [],
+      };
+      graph.children.push(child);
+      nodeDb[node.id] = child;
       await addVertices(nodeEl, nodeArr, child, node.id);
 
       if (node.label) {
@@ -75,28 +100,16 @@ export const render = async (
   };
 
   const addVertices = async function (
-    nodeEl: any,
-    nodeArr: any[],
-    graph: {
-      id: string;
-      layoutOptions: {
-        'elk.hierarchyHandling': string;
-        'elk.algorithm': any;
-        'nodePlacement.strategy': any;
-        'elk.layered.mergeEdges': any;
-        'elk.direction': string;
-        'spacing.baseValue': number;
-      };
-      children: never[];
-      edges: never[];
-    },
-    parentId?: undefined
+    nodeEl: SVGGroup,
+    nodeArr: Node[],
+    graph: { children: NodeWithVertex[] },
+    parentId?: string
   ) {
-    const siblings = nodeArr.filter((node: { parentId: any }) => node.parentId === parentId);
+    const siblings = nodeArr.filter((node) => node?.parentId === parentId);
     log.info('addVertices APA12', siblings, parentId);
     // Iterate through each item in the vertex object (containing all the vertices found) in the graph definition
     await Promise.all(
-      siblings.map(async (node: any) => {
+      siblings.map(async (node) => {
         await addVertex(nodeEl, graph, nodeArr, node);
       })
     );
diff --git a/packages/mermaid/src/rendering-util/createText.ts b/packages/mermaid/src/rendering-util/createText.ts
index 4eb8a275b..9d84600c4 100644
--- a/packages/mermaid/src/rendering-util/createText.ts
+++ b/packages/mermaid/src/rendering-util/createText.ts
@@ -207,7 +207,7 @@ export const createText = async (
     width = 200,
     addSvgBackground = false,
   } = {},
-  config: MermaidConfig
+  config?: MermaidConfig
 ) => {
   log.debug(
     'XYZ createText',
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/nodes.spec.ts b/packages/mermaid/src/rendering-util/rendering-elements/nodes.spec.ts
index a7a7691e5..c1f0e1437 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/nodes.spec.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/nodes.spec.ts
@@ -84,7 +84,7 @@ describe('Test Alias for shapes', function () {
   });
 
   it('should support alias for shadedProcess shape ', function () {
-    const aliases = ['lined-process', 'lined-rectangle', 'lin-proc', 'lin-rect'];
+    const aliases = ['lined-process', 'lined-rectangle', 'lin-proc', 'lin-rect'] as const;
     for (const alias of aliases) {
       expect(shapes[alias]).toBe(shapes['shaded-process']);
     }
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/nodes.js b/packages/mermaid/src/rendering-util/rendering-elements/nodes.ts
similarity index 60%
rename from packages/mermaid/src/rendering-util/rendering-elements/nodes.js
rename to packages/mermaid/src/rendering-util/rendering-elements/nodes.ts
index 4a9cfac57..2deb9ec64 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/nodes.js
+++ b/packages/mermaid/src/rendering-util/rendering-elements/nodes.ts
@@ -1,10 +1,18 @@
 import { log } from '../../logger.js';
 import { shapes } from './shapes.js';
+import type { Node, ShapeRenderOptions } from '../types.js';
+import type { SVGGroup } from '../../mermaid.js';
+import type { D3Selection } from '../../types.js';
+import { handleUndefinedAttr } from '../../utils.js';
+import type { graphlib } from 'dagre-d3-es';
 
-const nodeElems = new Map();
+type ShapeHandler = (typeof shapes)[keyof typeof shapes];
+type NodeElement = D3Selection<SVGAElement> | Awaited<ReturnType<ShapeHandler>>;
 
-export const insertNode = async (elem, node, renderOptions) => {
-  let newEl;
+const nodeElems = new Map<string, NodeElement>();
+
+export async function insertNode(elem: SVGGroup, node: Node, renderOptions: ShapeRenderOptions) {
+  let newEl: NodeElement | undefined;
   let el;
 
   //special check for rect shape (with or without rounded corners)
@@ -16,7 +24,7 @@ export const insertNode = async (elem, node, renderOptions) => {
     }
   }
 
-  const shapeHandler = shapes[node.shape];
+  const shapeHandler = shapes[(node.shape ?? 'undefined') as keyof typeof shapes];
 
   if (!shapeHandler) {
     throw new Error(`No such shape: ${node.shape}. Please check your syntax.`);
@@ -30,7 +38,10 @@ export const insertNode = async (elem, node, renderOptions) => {
     } else if (node.linkTarget) {
       target = node.linkTarget || '_blank';
     }
-    newEl = elem.insert('svg:a').attr('xlink:href', node.link).attr('target', target);
+    newEl = elem
+      .insert<SVGAElement>('svg:a')
+      .attr('xlink:href', node.link)
+      .attr('target', target ?? null);
     el = await shapeHandler(newEl, node, renderOptions);
   } else {
     el = await shapeHandler(elem, node, renderOptions);
@@ -40,7 +51,7 @@ export const insertNode = async (elem, node, renderOptions) => {
   newEl.attr('data-id', node.id);
   newEl.attr('data-node', true);
   newEl.attr('data-et', 'node');
-  newEl.attr('data-look', node.look);
+  newEl.attr('data-look', handleUndefinedAttr(node.look));
 
   if (node.tooltip) {
     el.attr('title', node.tooltip);
@@ -49,12 +60,12 @@ export const insertNode = async (elem, node, renderOptions) => {
   nodeElems.set(node.id, newEl);
 
   if (node.haveCallback) {
-    nodeElems.get(node.id).attr('class', nodeElems.get(node.id).attr('class') + ' clickable');
+    newEl.attr('class', newEl.attr('class') + ' clickable');
   }
   return newEl;
-};
+}
 
-export const setNodeElem = (elem, node) => {
+export const setNodeElem = (elem: NodeElement, node: Pick<Node, 'id'>) => {
   nodeElems.set(node.id, elem);
 };
 
@@ -62,8 +73,8 @@ export const clear = () => {
   nodeElems.clear();
 };
 
-export const positionNode = (node) => {
-  const el = nodeElems.get(node.id);
+export const positionNode = (node: ReturnType<graphlib.Graph['node']>) => {
+  const el = nodeElems.get(node.id)!;
   log.trace(
     'Transforming node',
     node.diff,
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes.ts
index b336fc823..89beb85e0 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes.ts
@@ -1,3 +1,5 @@
+import type { Entries } from 'type-fest';
+import type { D3Selection, MaybePromise } from '../../types.js';
 import type { Node, ShapeRenderOptions } from '../types.js';
 import { anchor } from './shapes/anchor.js';
 import { bowTieRect } from './shapes/bowTieRect.js';
@@ -56,8 +58,11 @@ import { waveEdgedRectangle } from './shapes/waveEdgedRectangle.js';
 import { waveRectangle } from './shapes/waveRectangle.js';
 import { windowPane } from './shapes/windowPane.js';
 
-// eslint-disable-next-line @typescript-eslint/no-explicit-any
-type ShapeHandler = (parent: any, node: Node, options: ShapeRenderOptions) => unknown;
+type ShapeHandler = <T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node,
+  options: ShapeRenderOptions
+) => MaybePromise<D3Selection<SVGGElement>>;
 
 export interface ShapeDefinition {
   semanticName: string;
@@ -75,7 +80,7 @@ export interface ShapeDefinition {
   handler: ShapeHandler;
 }
 
-export const shapesDefs: ShapeDefinition[] = [
+export const shapesDefs = [
   {
     semanticName: 'Process',
     name: 'Rectangle',
@@ -442,11 +447,11 @@ export const shapesDefs: ShapeDefinition[] = [
     aliases: ['lined-document'],
     handler: linedWaveEdgedRect,
   },
-];
+] as const satisfies ShapeDefinition[];
 
 const generateShapeMap = () => {
   // These are the shapes that didn't have documentation present
-  const shapeMap: Record<string, ShapeHandler> = {
+  const undocumentedShapes = {
     // States
     state,
     choice,
@@ -464,18 +469,25 @@ const generateShapeMap = () => {
     imageSquare,
 
     anchor,
-  };
+  } as const;
 
-  for (const shape of shapesDefs) {
-    for (const alias of [
-      shape.shortName,
-      ...(shape.aliases ?? []),
-      ...(shape.internalAliases ?? []),
-    ]) {
-      shapeMap[alias] = shape.handler;
-    }
-  }
-  return shapeMap;
+  const entries = [
+    ...(Object.entries(undocumentedShapes) as Entries<typeof undocumentedShapes>),
+    ...shapesDefs.flatMap((shape) => {
+      const aliases = [
+        shape.shortName,
+        ...('aliases' in shape ? shape.aliases : []),
+        ...('internalAliases' in shape ? shape.internalAliases : []),
+      ];
+      return aliases.map((alias) => [alias, shape.handler] as const);
+    }),
+  ];
+  return Object.fromEntries(entries) as Record<
+    (typeof entries)[number][0],
+    (typeof entries)[number][1]
+  > satisfies Record<string, ShapeHandler>;
 };
 
 export const shapes = generateShapeMap();
+
+export type ShapeID = keyof typeof shapes;
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/anchor.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/anchor.ts
index af2f1cd63..11821a11b 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/anchor.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/anchor.ts
@@ -1,11 +1,13 @@
 import { log } from '../../../logger.js';
 import { updateNodeBounds, getNodeClasses } from './util.js';
 import intersect from '../intersect/index.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
+import { handleUndefinedAttr } from '../../../utils.js';
+import type { D3Selection } from '../../../types.js';
 
-export const anchor = (parent: SVGAElement, node: Node): Promise<SVGAElement> => {
+export function anchor<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   const { labelStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const classes = getNodeClasses(node);
@@ -14,7 +16,6 @@ export const anchor = (parent: SVGAElement, node: Node): Promise<SVGAElement> =>
     cssClasses = 'anchor';
   }
   const shapeSvg = parent
-    // @ts-ignore - SVGElement is not typed
     .insert('g')
     .attr('class', cssClasses)
     .attr('id', node.domId || node.id);
@@ -23,6 +24,7 @@ export const anchor = (parent: SVGAElement, node: Node): Promise<SVGAElement> =>
 
   const { cssStyles } = node;
 
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, { fill: 'black', stroke: 'none', fillStyle: 'solid' });
 
@@ -31,7 +33,7 @@ export const anchor = (parent: SVGAElement, node: Node): Promise<SVGAElement> =>
   }
   const roughNode = rc.circle(0, 0, radius * 2, options);
   const circleElem = shapeSvg.insert(() => roughNode, ':first-child');
-  circleElem.attr('class', 'anchor').attr('style', cssStyles);
+  circleElem.attr('class', 'anchor').attr('style', handleUndefinedAttr(cssStyles));
 
   updateNodeBounds(node, circleElem);
 
@@ -41,4 +43,4 @@ export const anchor = (parent: SVGAElement, node: Node): Promise<SVGAElement> =>
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/bowTieRect.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/bowTieRect.ts
index 2690f8579..164473645 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/bowTieRect.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/bowTieRect.ts
@@ -1,8 +1,9 @@
 import { labelHelper, updateNodeBounds, getNodeClasses, createPathFromPoints } from './util.js';
 import intersect from '../intersect/index.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
+import type { D3Selection } from '../../../types.js';
 
 function generateArcPoints(
   x1: number,
@@ -84,7 +85,7 @@ function calculateArcSagitta(chord: number, radiusX: number, radiusY: number) {
   return semiMinorAxis * (1 - Math.sqrt(1 - (chord / semiMajorAxis / 2) ** 2));
 }
 
-export const bowTieRect = async (parent: SVGAElement, node: Node) => {
+export async function bowTieRect<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const nodePadding = node.padding ?? 0;
@@ -132,6 +133,7 @@ export const bowTieRect = async (parent: SVGAElement, node: Node) => {
     ...generateArcPoints(w / 2, h / 2, w / 2, -h / 2, rx, ry, true),
   ];
 
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, {});
 
@@ -163,4 +165,4 @@ export const bowTieRect = async (parent: SVGAElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/card.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/card.ts
index edc7c538f..6a8597402 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/card.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/card.ts
@@ -1,11 +1,12 @@
 import { labelHelper, updateNodeBounds, getNodeClasses } from './util.js';
 import intersect from '../intersect/index.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
 
 import { insertPolygonShape } from './insertPolygonShape.js';
 import { createPathFromPoints } from './util.js';
+import type { D3Selection } from '../../../types.js';
 
 // const createPathFromPoints = (points: { x: number; y: number }[]): string => {
 //   const pointStrings = points.map((p, i) => `${i === 0 ? 'M' : 'L'}${p.x},${p.y}`);
@@ -16,7 +17,7 @@ import { createPathFromPoints } from './util.js';
 /// Size of the notch on the top left corner
 const NOTCH_SIZE = 12;
 
-export async function card(parent: SVGAElement, node: Node): Promise<SVGAElement> {
+export async function card<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
 
@@ -49,10 +50,11 @@ export async function card(parent: SVGAElement, node: Node): Promise<SVGAElement
     { x: left + NOTCH_SIZE, y: top },
   ];
 
-  let polygon: d3.Selection<SVGPolygonElement | SVGGElement, unknown, null, undefined>;
+  let polygon: D3Selection<SVGGElement> | Awaited<ReturnType<typeof insertPolygonShape>>;
   const { cssStyles } = node;
 
   if (node.look === 'handDrawn') {
+    // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
     const rc = rough.svg(shapeSvg);
     const options = userNodeOverrides(node, {});
     const pathData = createPathFromPoints(points);
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/choice.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/choice.ts
index 6cb747898..4edd68587 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/choice.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/choice.ts
@@ -1,12 +1,11 @@
 import intersect from '../intersect/index.js';
 import type { Node } from '../../types.js';
-import type { SVG } from '../../../diagram-api/types.js';
-// @ts-ignore TODO: Fix rough typings
 import rough from 'roughjs';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import { createPathFromPoints, getNodeClasses } from './util.js';
+import type { D3Selection } from '../../../types.js';
 
-export const choice = (parent: SVG, node: Node) => {
+export function choice<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   const { nodeStyles } = styles2String(node);
   node.label = '';
   const shapeSvg = parent
@@ -24,7 +23,7 @@ export const choice = (parent: SVG, node: Node) => {
     { x: -s / 2, y: 0 },
   ];
 
-  // @ts-ignore TODO: Fix rough typings
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, {});
 
@@ -53,4 +52,4 @@ export const choice = (parent: SVG, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/circle.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/circle.ts
index 2d237f158..c2790d61a 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/circle.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/circle.ts
@@ -4,8 +4,10 @@ import intersect from '../intersect/index.js';
 import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
+import type { D3Selection } from '../../../types.js';
+import { handleUndefinedAttr } from '../../../utils.js';
 
-export const circle = async (parent: SVGAElement, node: Node): Promise<SVGAElement> => {
+export async function circle<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   // If incoming height & width are present, subtract the padding from them
@@ -24,12 +26,13 @@ export const circle = async (parent: SVGAElement, node: Node): Promise<SVGAEleme
   const { cssStyles } = node;
 
   if (node.look === 'handDrawn') {
+    // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
     const rc = rough.svg(shapeSvg);
     const options = userNodeOverrides(node, {});
     const roughNode = rc.circle(0, 0, radius * 2, options);
 
     circleElem = shapeSvg.insert(() => roughNode, ':first-child');
-    circleElem.attr('class', 'basic label-container').attr('style', cssStyles);
+    circleElem.attr('class', 'basic label-container').attr('style', handleUndefinedAttr(cssStyles));
   } else {
     circleElem = shapeSvg
       .insert('circle', ':first-child')
@@ -48,4 +51,4 @@ export const circle = async (parent: SVGAElement, node: Node): Promise<SVGAEleme
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/crossedCircle.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/crossedCircle.ts
index 0c9e61552..97afc984d 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/crossedCircle.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/crossedCircle.ts
@@ -1,10 +1,10 @@
-import rough from 'roughjs';
-import type { SVG } from '../../../diagram-api/types.js';
 import { log } from '../../../logger.js';
-import type { Node } from '../../types.d.ts';
+import { getNodeClasses, updateNodeBounds } from './util.js';
+import type { Node } from '../../types.js';
+import rough from 'roughjs';
 import intersect from '../intersect/index.js';
 import { userNodeOverrides } from './handDrawnShapeStyles.js';
-import { getNodeClasses, updateNodeBounds } from './util.js';
+import type { D3Selection } from '../../../types.js';
 
 function createLine(r: number) {
   const axis45 = Math.SQRT1_2; // cosine of 45 degrees = 1/sqrt(2)
@@ -19,7 +19,7 @@ function createLine(r: number) {
                    M ${pointQ1.x},${pointQ1.y} L ${pointQ3.x},${pointQ3.y}`;
 }
 
-export const crossedCircle = (parent: SVG, node: Node) => {
+export function crossedCircle<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   node.label = '';
   const shapeSvg = parent
     .insert('g')
@@ -28,7 +28,7 @@ export const crossedCircle = (parent: SVG, node: Node) => {
   const radius = node?.width ? node?.width / 2 : node?.height ? node?.height / 2 : 25;
   const { cssStyles } = node;
 
-  // @ts-expect-error shapeSvg d3 class is incorrect?
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, {});
 
@@ -58,4 +58,4 @@ export const crossedCircle = (parent: SVG, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/curlyBraceLeft.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/curlyBraceLeft.ts
index fe8f6008c..060451a5e 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/curlyBraceLeft.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/curlyBraceLeft.ts
@@ -1,8 +1,9 @@
 import { labelHelper, updateNodeBounds, getNodeClasses, createPathFromPoints } from './util.js';
 import intersect from '../intersect/index.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
+import type { D3Selection } from '../../../types.js';
 
 function generateCirclePoints(
   centerX: number,
@@ -34,7 +35,10 @@ function generateCirclePoints(
   return points;
 }
 
-export const curlyBraceLeft = async (parent: SVGAElement, node: Node) => {
+export async function curlyBraceLeft<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node
+) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const { shapeSvg, bbox, label } = await labelHelper(parent, node, getNodeClasses(node));
@@ -84,6 +88,7 @@ export const curlyBraceLeft = async (parent: SVGAElement, node: Node) => {
     { x: w / 2, y: h / 2 + radius },
   ];
 
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, { fill: 'none' });
 
@@ -126,4 +131,4 @@ export const curlyBraceLeft = async (parent: SVGAElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/curlyBraceRight.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/curlyBraceRight.ts
index d406eee47..7f7ab4200 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/curlyBraceRight.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/curlyBraceRight.ts
@@ -1,8 +1,9 @@
 import { labelHelper, updateNodeBounds, getNodeClasses, createPathFromPoints } from './util.js';
 import intersect from '../intersect/index.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
+import type { D3Selection } from '../../../types.js';
 
 function generateCirclePoints(
   centerX: number,
@@ -34,7 +35,10 @@ function generateCirclePoints(
   return points;
 }
 
-export const curlyBraceRight = async (parent: SVGAElement, node: Node) => {
+export async function curlyBraceRight<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node
+) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const { shapeSvg, bbox, label } = await labelHelper(parent, node, getNodeClasses(node));
@@ -87,6 +91,7 @@ export const curlyBraceRight = async (parent: SVGAElement, node: Node) => {
     { x: -w / 2, y: h / 2 + radius },
   ];
 
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, { fill: 'none' });
 
@@ -130,4 +135,4 @@ export const curlyBraceRight = async (parent: SVGAElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/curlyBraces.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/curlyBraces.ts
index ad30d6eb9..97f5953f1 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/curlyBraces.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/curlyBraces.ts
@@ -1,8 +1,9 @@
 import { labelHelper, updateNodeBounds, getNodeClasses, createPathFromPoints } from './util.js';
 import intersect from '../intersect/index.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
+import type { D3Selection } from '../../../types.js';
 
 function generateCirclePoints(
   centerX: number,
@@ -34,7 +35,10 @@ function generateCirclePoints(
   return points;
 }
 
-export const curlyBraces = async (parent: SVGAElement, node: Node) => {
+export async function curlyBraces<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node
+) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const { shapeSvg, bbox, label } = await labelHelper(parent, node, getNodeClasses(node));
@@ -101,6 +105,7 @@ export const curlyBraces = async (parent: SVGAElement, node: Node) => {
     ...generateCirclePoints(-w / 2 + radius + radius / 2, h / 2, radius, 30, -180, -270),
   ];
 
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, { fill: 'transparent' });
 
@@ -142,4 +147,4 @@ export const curlyBraces = async (parent: SVGAElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/curvedTrapezoid.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/curvedTrapezoid.ts
index 1068a5304..c70c66bf8 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/curvedTrapezoid.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/curvedTrapezoid.ts
@@ -6,11 +6,15 @@ import {
   generateCirclePoints,
 } from './util.js';
 import intersect from '../intersect/index.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
+import type { D3Selection } from '../../../types.js';
 
-export const curvedTrapezoid = async (parent: SVGAElement, node: Node) => {
+export async function curvedTrapezoid<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node
+) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const nodePadding = node.padding ?? 0;
@@ -39,6 +43,7 @@ export const curvedTrapezoid = async (parent: SVGAElement, node: Node) => {
   const radius = h / 2;
 
   const { cssStyles } = node;
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, {});
 
@@ -85,4 +90,4 @@ export const curvedTrapezoid = async (parent: SVGAElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/cylinder.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/cylinder.ts
index aa08b8111..76fa7b388 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/cylinder.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/cylinder.ts
@@ -4,6 +4,8 @@ import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import { getConfig } from '../../../config.js';
 import rough from 'roughjs';
+import type { D3Selection } from '../../../types.js';
+import { handleUndefinedAttr } from '../../../utils.js';
 
 export const createCylinderPathD = (
   x: number,
@@ -52,7 +54,7 @@ export const createInnerCylinderPathD = (
 
 const MIN_HEIGHT = 8;
 const MIN_WIDTH = 8;
-export const cylinder = async (parent: SVGAElement, node: Node) => {
+export async function cylinder<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   const { themeVariables } = getConfig();
   const { useGradient } = themeVariables;
   const { labelStyles, nodeStyles } = styles2String(node);
@@ -85,10 +87,11 @@ export const cylinder = async (parent: SVGAElement, node: Node) => {
   const ry = rx / (2.5 + w / 50);
   const h = (node.height ? node.height : bbox.height) + labelPaddingX + ry;
 
-  let cylinder: d3.Selection<SVGPathElement | SVGGElement, unknown, null, undefined>;
+  let cylinder: D3Selection<SVGPathElement> | D3Selection<SVGGElement>;
   const { cssStyles } = node;
 
   if (node.look === 'handDrawn' || (node.look === 'neo' && !useGradient)) {
+    // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
     const rc = rough.svg(shapeSvg);
     const outerPathData = createOuterCylinderPathD(0, 0, w, h, rx, ry);
     const innerPathData = createInnerCylinderPathD(0, ry, w, h, rx, ry);
@@ -118,7 +121,7 @@ export const cylinder = async (parent: SVGAElement, node: Node) => {
       .insert('path', ':first-child')
       .attr('d', pathData)
       .attr('class', 'basic label-container')
-      .attr('style', cssStyles)
+      .attr('style', handleUndefinedAttr(cssStyles))
       .attr('style', nodeStyles);
   }
 
@@ -159,4 +162,4 @@ export const cylinder = async (parent: SVGAElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/dividedRect.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/dividedRect.ts
index 68269f5c7..571466fab 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/dividedRect.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/dividedRect.ts
@@ -1,10 +1,14 @@
 import { labelHelper, updateNodeBounds, getNodeClasses } from './util.js';
 import intersect from '../intersect/index.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
+import type { D3Selection } from '../../../types.js';
 
-export const dividedRectangle = async (parent: SVGAElement, node: Node) => {
+export async function dividedRectangle<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node
+) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
 
@@ -34,6 +38,7 @@ export const dividedRectangle = async (parent: SVGAElement, node: Node) => {
 
   const { cssStyles } = node;
 
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, {});
   if (node.look !== 'handDrawn') {
@@ -81,4 +86,4 @@ export const dividedRectangle = async (parent: SVGAElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/document.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/document.ts
index 9a76047f4..d5ea3aa76 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/document.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/document.ts
@@ -1,8 +1,10 @@
 import { labelHelper, updateNodeBounds, getNodeClasses } from './util.js';
 import intersect from '../intersect/index.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
+import type { D3Selection } from '../../../types.js';
+import { handleUndefinedAttr } from '../../../utils.js';
 
 export const createCylinderPathD = (
   x: number,
@@ -48,7 +50,7 @@ export const createInnerCylinderPathD = (
 ): string => {
   return [`M${x - width / 2},${-height / 2}`, `a${rx},${ry} 0,0,0 ${width},0`].join(' ');
 };
-export const cylinder = async (parent: SVGAElement, node: Node) => {
+export async function cylinder<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const { shapeSvg, bbox } = await labelHelper(parent, node, getNodeClasses(node));
@@ -57,10 +59,11 @@ export const cylinder = async (parent: SVGAElement, node: Node) => {
   const ry = rx / (2.5 + w / 50);
   const h = bbox.height + ry + node.padding;
 
-  let cylinder: d3.Selection<SVGPathElement | SVGGElement, unknown, null, undefined>;
+  let cylinder: D3Selection<SVGPathElement> | D3Selection<SVGGElement>;
   const { cssStyles } = node;
 
   if (node.look === 'handDrawn') {
+    // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
     const rc = rough.svg(shapeSvg);
     const outerPathData = createOuterCylinderPathD(0, 0, w, h, rx, ry);
     const innerPathData = createInnerCylinderPathD(0, ry, w, h, rx, ry);
@@ -79,7 +82,7 @@ export const cylinder = async (parent: SVGAElement, node: Node) => {
       .insert('path', ':first-child')
       .attr('d', pathData)
       .attr('class', 'basic label-container')
-      .attr('style', cssStyles)
+      .attr('style', handleUndefinedAttr(cssStyles))
       .attr('style', nodeStyles);
   }
 
@@ -114,4 +117,4 @@ export const cylinder = async (parent: SVGAElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/doubleCircle.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/doubleCircle.ts
index fa85ffa49..426d76471 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/doubleCircle.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/doubleCircle.ts
@@ -4,8 +4,13 @@ import intersect from '../intersect/index.js';
 import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
+import type { D3Selection } from '../../../types.js';
+import { handleUndefinedAttr } from '../../../utils.js';
 
-export const doublecircle = async (parent: SVGAElement, node: Node): Promise<SVGAElement> => {
+export async function doublecircle<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node
+) {
   const { labelStyles, nodeStyles } = styles2String(node);
   const gap = 5;
   node.labelStyle = labelStyles;
@@ -30,6 +35,7 @@ export const doublecircle = async (parent: SVGAElement, node: Node): Promise<SVG
   const { cssStyles } = node;
 
   if (node.look === 'handDrawn') {
+    // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
     const rc = rough.svg(shapeSvg);
     const outerOptions = userNodeOverrides(node, { roughness: 0.2, strokeWidth: 2.5 });
 
@@ -39,7 +45,9 @@ export const doublecircle = async (parent: SVGAElement, node: Node): Promise<SVG
 
     circleGroup = shapeSvg.insert('g', ':first-child');
     // circleGroup = circleGroup.insert(() => outerRoughNode, ':first-child');
-    circleGroup.attr('class', node.cssClasses).attr('style', cssStyles);
+    circleGroup
+      .attr('class', handleUndefinedAttr(node.cssClasses))
+      .attr('style', handleUndefinedAttr(cssStyles));
 
     circleGroup.node()?.appendChild(outerRoughNode);
     circleGroup.node()?.appendChild(innerRoughNode);
@@ -73,4 +81,4 @@ export const doublecircle = async (parent: SVGAElement, node: Node): Promise<SVG
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/drawRect.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/drawRect.ts
index 29b404b6a..0e8f3b99f 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/drawRect.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/drawRect.ts
@@ -4,8 +4,14 @@ import type { Node, RectOptions } from '../../types.js';
 import { createRoundedRectPathD } from './roundedRectPath.js';
 import { userNodeOverrides, styles2String } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
+import type { D3Selection } from '../../../types.js';
+import { handleUndefinedAttr } from '../../../utils.js';
 
-export const drawRect = async (parent: SVGAElement, node: Node, options: RectOptions) => {
+export async function drawRect<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node,
+  options: RectOptions
+) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   // If incoming height & width are present, subtract the padding from them
@@ -45,7 +51,7 @@ export const drawRect = async (parent: SVGAElement, node: Node, options: RectOpt
         : rc.rectangle(x, y, totalWidth, totalHeight, options);
 
     rect = shapeSvg.insert(() => roughNode, ':first-child');
-    rect.attr('class', 'basic label-container').attr('style', cssStyles);
+    rect.attr('class', 'basic label-container').attr('style', handleUndefinedAttr(cssStyles));
   } else {
     rect = shapeSvg.insert('rect', ':first-child');
 
@@ -54,9 +60,9 @@ export const drawRect = async (parent: SVGAElement, node: Node, options: RectOpt
     rect
       .attr('class', rectClass)
       .attr('style', nodeStyles)
-      .attr('rx', rx)
+      .attr('rx', handleUndefinedAttr(rx))
       .attr('data-id', node.id)
-      .attr('ry', ry)
+      .attr('ry', handleUndefinedAttr(ry))
       .attr('x', x)
       .attr('y', y)
       .attr('width', totalWidth)
@@ -71,4 +77,4 @@ export const drawRect = async (parent: SVGAElement, node: Node, options: RectOpt
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/filledCircle.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/filledCircle.ts
index e9989d4ae..e3215e2df 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/filledCircle.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/filledCircle.ts
@@ -1,16 +1,16 @@
 import rough from 'roughjs';
-import type { SVG } from '../../../diagram-api/types.js';
 import { log } from '../../../logger.js';
-import type { Node, ShapeRenderOptions } from '../../types.ts';
+import type { Node, ShapeRenderOptions } from '../../types.js';
 import intersect from '../intersect/index.js';
 import { userNodeOverrides } from './handDrawnShapeStyles.js';
 import { getNodeClasses, updateNodeBounds } from './util.js';
+import type { D3Selection } from '../../../types.js';
 
-export const filledCircle = (
-  parent: SVG,
+export function filledCircle<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
   node: Node,
   { config: { themeVariables } }: ShapeRenderOptions
-) => {
+) {
   node.label = '';
 
   // If incoming height & width are present, subtract the padding from them
@@ -42,7 +42,7 @@ export const filledCircle = (
   const radius = (node.width ?? 0) / 2;
   const { cssStyles } = node;
 
-  // @ts-expect-error shapeSvg d3 class is incorrect?
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const { nodeBorder } = themeVariables;
   const options = userNodeOverrides(node, { fillStyle: 'solid' });
@@ -70,4 +70,4 @@ export const filledCircle = (
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/flippedTriangle.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/flippedTriangle.ts
index d3e0924b4..f1abf0e33 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/flippedTriangle.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/flippedTriangle.ts
@@ -1,14 +1,18 @@
 import { log } from '../../../logger.js';
 import { labelHelper, updateNodeBounds, getNodeClasses } from './util.js';
 import intersect from '../intersect/index.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
 import { createPathFromPoints } from './util.js';
+import type { D3Selection } from '../../../types.js';
 
 const MIN_HEIGHT = 10;
 const MIN_WIDTH = 10;
-export const flippedTriangle = async (parent: SVGAElement, node: Node): Promise<SVGAElement> => {
+export async function flippedTriangle<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node
+) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
 
@@ -41,6 +45,7 @@ export const flippedTriangle = async (parent: SVGAElement, node: Node): Promise<
 
   const { cssStyles } = node;
 
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, {});
   if (node.look !== 'handDrawn') {
@@ -78,4 +83,4 @@ export const flippedTriangle = async (parent: SVGAElement, node: Node): Promise<
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/forkJoin.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/forkJoin.ts
index f68a0c93e..4f3701944 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/forkJoin.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/forkJoin.ts
@@ -1,15 +1,15 @@
 import rough from 'roughjs';
-import type { SVG } from '../../../diagram-api/types.js';
 import type { Node, ShapeRenderOptions } from '../../types.js';
 import intersect from '../intersect/index.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import { getNodeClasses, updateNodeBounds } from './util.js';
+import type { D3Selection } from '../../../types.js';
 
-export const forkJoin = (
-  parent: SVG,
+export function forkJoin<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
   node: Node,
   { dir, config: { state, themeVariables } }: ShapeRenderOptions
-) => {
+) {
   const { nodeStyles } = styles2String(node);
   node.label = '';
   const shapeSvg = parent
@@ -29,7 +29,7 @@ export const forkJoin = (
   const x = (-1 * width) / 2;
   const y = (-1 * height) / 2;
 
-  // @ts-ignore TODO: Fix rough typings
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, {
     stroke: themeVariables.lineColor,
@@ -63,4 +63,4 @@ export const forkJoin = (
     return intersect.rect(node, point);
   };
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/halfRoundedRectangle.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/halfRoundedRectangle.ts
index 16c54b123..83ff8580b 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/halfRoundedRectangle.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/halfRoundedRectangle.ts
@@ -7,11 +7,15 @@ import {
   generateCirclePoints,
 } from './util.js';
 import intersect from '../intersect/index.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
+import type { D3Selection } from '../../../types.js';
 
-export const halfRoundedRectangle = async (parent: SVGAElement, node: Node) => {
+export async function halfRoundedRectangle<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node
+) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const minWidth = 15,
@@ -39,6 +43,7 @@ export const halfRoundedRectangle = async (parent: SVGAElement, node: Node) => {
   const radius = h / 2;
   const { cssStyles } = node;
 
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, {});
 
@@ -81,4 +86,4 @@ export const halfRoundedRectangle = async (parent: SVGAElement, node: Node) => {
     return pos;
   };
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/hexagon.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/hexagon.ts
index cab5dc5ee..f752e5000 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/hexagon.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/hexagon.ts
@@ -3,8 +3,8 @@ import intersect from '../intersect/index.js';
 import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
-
 import { insertPolygonShape } from './insertPolygonShape.js';
+import type { D3Selection } from '../../../types.js';
 
 export const createHexagonPathD = (
   x: number,
@@ -24,7 +24,7 @@ export const createHexagonPathD = (
   ].join(' ');
 };
 
-export const hexagon = async (parent: SVGAElement, node: Node): Promise<SVGAElement> => {
+export async function hexagon<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   const { labelStyles, nodeStyles } = styles2String(node);
   const f = 4;
   node.labelStyle = labelStyles;
@@ -53,10 +53,11 @@ export const hexagon = async (parent: SVGAElement, node: Node): Promise<SVGAElem
     { x: 0, y: -h / 2 },
   ];
 
-  let polygon: d3.Selection<SVGPolygonElement | SVGGElement, unknown, null, undefined>;
+  let polygon: D3Selection<SVGGElement> | Awaited<ReturnType<typeof insertPolygonShape>>;
   const { cssStyles } = node;
 
   if (node.look === 'handDrawn') {
+    // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
     const rc = rough.svg(shapeSvg);
     const options = userNodeOverrides(node, {});
     const pathData = createHexagonPathD(0, 0, w, h, m);
@@ -87,4 +88,4 @@ export const hexagon = async (parent: SVGAElement, node: Node): Promise<SVGAElem
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/hourglass.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/hourglass.ts
index 4c9d586e3..1b355203d 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/hourglass.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/hourglass.ts
@@ -2,10 +2,11 @@ import rough from 'roughjs';
 import { log } from '../../../logger.js';
 import { labelHelper, updateNodeBounds, getNodeClasses, createPathFromPoints } from './util.js';
 import intersect from '../intersect/index.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import { userNodeOverrides } from './handDrawnShapeStyles.js';
+import type { D3Selection } from '../../../types.js';
 
-export const hourglass = async (parent: SVGAElement, node: Node) => {
+export async function hourglass<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   node.label = '';
   const { shapeSvg } = await labelHelper(parent, node, getNodeClasses(node));
 
@@ -14,6 +15,7 @@ export const hourglass = async (parent: SVGAElement, node: Node) => {
 
   const { cssStyles } = node;
 
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, {});
 
@@ -49,4 +51,4 @@ export const hourglass = async (parent: SVGAElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/icon.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/icon.ts
index 05aa8eeda..789dfe430 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/icon.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/icon.ts
@@ -1,17 +1,17 @@
 import rough from 'roughjs';
-import type { SVG } from '../../../diagram-api/types.js';
 import { log } from '../../../logger.js';
 import { getIconSVG } from '../../icons.js';
-import type { Node, ShapeRenderOptions } from '../../types.ts';
+import type { Node, ShapeRenderOptions } from '../../types.js';
 import intersect from '../intersect/index.js';
 import { compileStyles, styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import { labelHelper, updateNodeBounds } from './util.js';
+import type { D3Selection } from '../../../types.js';
 
-export const icon = async (
-  parent: SVG,
+export async function icon<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
   node: Node,
   { config: { themeVariables, flowchart } }: ShapeRenderOptions
-) => {
+) {
   const { labelStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const assetHeight = node.assetHeight ?? 48;
@@ -33,6 +33,7 @@ export const icon = async (
 
   const labelPadding = node.label ? 8 : 0;
 
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, { stroke: 'none', fill: 'none' });
 
@@ -64,7 +65,7 @@ export const icon = async (
         fallbackPrefix: '',
       })}</g>`
     );
-    const iconBBox = iconElem.node().getBBox();
+    const iconBBox = iconElem.node()!.getBBox();
     const iconWidth = iconBBox.width;
     const iconHeight = iconBBox.height;
     const iconX = iconBBox.x;
@@ -79,9 +80,9 @@ export const icon = async (
     );
     iconElem.attr('style', `color : ${stylesMap.get('stroke') ?? nodeBorder};`);
     iconElem
-      .selectAll('path')
+      .selectAll<SVGPathElement, unknown>('path')
       .nodes()
-      .forEach((path: SVGPathElement) => {
+      .forEach((path) => {
         if (path.getAttribute('fill') === 'currentColor') {
           path.setAttribute('class', 'icon');
         }
@@ -150,4 +151,4 @@ export const icon = async (
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/iconCircle.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/iconCircle.ts
index 87ef798c5..598e352a1 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/iconCircle.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/iconCircle.ts
@@ -1,17 +1,17 @@
 import rough from 'roughjs';
-import type { SVG } from '../../../diagram-api/types.js';
 import { log } from '../../../logger.js';
 import { getIconSVG } from '../../icons.js';
-import type { Node, ShapeRenderOptions } from '../../types.ts';
+import type { Node, ShapeRenderOptions } from '../../types.js';
 import intersect from '../intersect/index.js';
 import { compileStyles, styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import { labelHelper, updateNodeBounds } from './util.js';
+import type { D3Selection } from '../../../types.js';
 
-export const iconCircle = async (
-  parent: SVG,
+export async function iconCircle<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
   node: Node,
   { config: { themeVariables, flowchart } }: ShapeRenderOptions
-) => {
+) {
   const { labelStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const defaultWidth = flowchart?.wrappingWidth;
@@ -48,6 +48,7 @@ export const iconCircle = async (
 
   const { nodeBorder } = themeVariables;
   const { stylesMap } = compileStyles(node);
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, { stroke: 'transparent' });
 
@@ -66,7 +67,7 @@ export const iconCircle = async (
       })}</g>`
     );
   }
-  const iconBBox = iconElem.node().getBBox();
+  const iconBBox = iconElem.node()!.getBBox();
   const iconWidth = iconBBox.width;
   // const iconHeight = iconBBox.height;
   const iconX = iconBBox.x;
@@ -96,9 +97,9 @@ export const iconCircle = async (
   );
   iconElem.attr('style', `color : ${stylesMap.get('stroke') ?? nodeBorder};`);
   iconElem
-    .selectAll('path')
+    .selectAll<SVGPathElement, unknown>('path')
     .nodes()
-    .forEach((path: SVGPathElement) => {
+    .forEach((path) => {
       if (path.getAttribute('fill') === 'currentColor') {
         path.setAttribute('class', 'icon');
       }
@@ -136,4 +137,4 @@ export const iconCircle = async (
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/iconRounded.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/iconRounded.ts
index a89ffe40e..338ad6e16 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/iconRounded.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/iconRounded.ts
@@ -1,18 +1,18 @@
 import rough from 'roughjs';
-import type { SVG } from '../../../diagram-api/types.js';
 import { log } from '../../../logger.js';
 import { getIconSVG } from '../../icons.js';
-import type { Node, ShapeRenderOptions } from '../../types.ts';
+import type { Node, ShapeRenderOptions } from '../../types.js';
 import intersect from '../intersect/index.js';
 import { compileStyles, styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import { createRoundedRectPathD } from './roundedRectPath.js';
 import { labelHelper, updateNodeBounds } from './util.js';
+import type { D3Selection } from '../../../types.js';
 
-export const iconRounded = async (
-  parent: SVG,
+export async function iconRounded<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
   node: Node,
   { config: { themeVariables, flowchart } }: ShapeRenderOptions
-) => {
+) {
   const { labelStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const defaultWidth = flowchart?.wrappingWidth;
@@ -51,6 +51,7 @@ export const iconRounded = async (
   const x = -width / 2;
   const y = -height / 2;
 
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, { stroke: 'transparent' });
 
@@ -78,7 +79,7 @@ export const iconRounded = async (
     iconElem.html(
       `<g>${await getIconSVG(node.icon, { height: iconSize, fallbackPrefix: '' })}</g>`
     );
-    const iconBBox = iconElem.node().getBBox();
+    const iconBBox = iconElem.node()!.getBBox();
     const iconWidth = iconBBox.width;
     // const iconHeight = iconBBox.height;
     const iconX = iconBBox.x;
@@ -89,9 +90,9 @@ export const iconRounded = async (
     );
     iconElem.attr('style', `color : ${stylesMap.get('stroke') ?? nodeBorder};`);
     iconElem
-      .selectAll('path')
+      .selectAll<SVGPathElement, unknown>('path')
       .nodes()
-      .forEach((path: SVGPathElement) => {
+      .forEach((path) => {
         if (path.getAttribute('fill') === 'currentColor') {
           path.setAttribute('class', 'icon');
         }
@@ -157,4 +158,4 @@ export const iconRounded = async (
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/iconSquare.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/iconSquare.ts
index c4c9f9a55..ea50cf730 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/iconSquare.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/iconSquare.ts
@@ -1,17 +1,17 @@
 import rough from 'roughjs';
-import type { SVG } from '../../../diagram-api/types.js';
 import { log } from '../../../logger.js';
 import { getIconSVG } from '../../icons.js';
-import type { Node, ShapeRenderOptions } from '../../types.ts';
+import type { Node, ShapeRenderOptions } from '../../types.js';
 import intersect from '../intersect/index.js';
 import { compileStyles, styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import { labelHelper, updateNodeBounds } from './util.js';
+import type { D3Selection } from '../../../types.js';
 
-export const iconSquare = async (
-  parent: SVG,
+export async function iconSquare<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
   node: Node,
   { config: { themeVariables, flowchart } }: ShapeRenderOptions
-) => {
+) {
   const { labelStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const defaultWidth = flowchart?.wrappingWidth;
@@ -54,6 +54,7 @@ export const iconSquare = async (
   const x = -width / 2;
   const y = -height / 2;
 
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, { stroke: 'transparent' });
 
@@ -80,7 +81,7 @@ export const iconSquare = async (
     iconElem.html(
       `<g>${await getIconSVG(node.icon, { height: iconSize, fallbackPrefix: '' })}</g>`
     );
-    const iconBBox = iconElem.node().getBBox();
+    const iconBBox = iconElem.node()!.getBBox();
     const iconWidth = iconBBox.width;
     // const iconHeight = iconBBox.height;
     const iconX = iconBBox.x;
@@ -91,9 +92,9 @@ export const iconSquare = async (
     );
     iconElem.attr('style', `color : ${stylesMap.get('stroke') ?? nodeBorder};`);
     iconElem
-      .selectAll('path')
+      .selectAll<SVGPathElement, unknown>('path')
       .nodes()
-      .forEach((path: SVGPathElement) => {
+      .forEach((path) => {
         if (path.getAttribute('fill') === 'currentColor') {
           path.setAttribute('class', 'icon');
         }
@@ -169,4 +170,4 @@ export const iconSquare = async (
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/imageSquare.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/imageSquare.ts
index edc1f1371..d6e7f561b 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/imageSquare.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/imageSquare.ts
@@ -1,15 +1,15 @@
-import type { SVG } from '../../../diagram-api/types.js';
 import { log } from '../../../logger.js';
-import type { Node, ShapeRenderOptions } from '../../types.ts';
+import type { Node, ShapeRenderOptions } from '../../types.js';
 import intersect from '../intersect/index.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import { labelHelper, updateNodeBounds } from './util.js';
+import type { D3Selection } from '../../../types.js';
 
-export const imageSquare = async (
-  parent: SVG,
+export async function imageSquare<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
   node: Node,
   { config: { flowchart } }: ShapeRenderOptions
-) => {
+) {
   const img = new Image();
   img.src = node?.img ?? '';
   await img.decode();
@@ -161,4 +161,4 @@ export const imageSquare = async (
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/insertPolygonShape.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/insertPolygonShape.ts
index 6c00b9523..874996444 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/insertPolygonShape.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/insertPolygonShape.ts
@@ -1,5 +1,7 @@
-export function insertPolygonShape(
-  parent: any,
+import type { D3Selection } from '../../../types.js';
+
+export function insertPolygonShape<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
   w: number,
   h: number,
   points: { x: number; y: number }[]
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/invertedTrapezoid.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/invertedTrapezoid.ts
index 48fa8e529..1ca28e824 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/invertedTrapezoid.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/invertedTrapezoid.ts
@@ -4,6 +4,7 @@ import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
 import { insertPolygonShape } from './insertPolygonShape.js';
+import type { D3Selection } from '../../../types.js';
 
 // export const createInvertedTrapezoidPathD = (
 //   x: number,
@@ -20,7 +21,10 @@ import { insertPolygonShape } from './insertPolygonShape.js';
 //   ].join(' ');
 // };
 
-export const inv_trapezoid = async (parent: SVGAElement, node: Node): Promise<SVGAElement> => {
+export async function inv_trapezoid<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node
+) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
 
@@ -51,10 +55,11 @@ export const inv_trapezoid = async (parent: SVGAElement, node: Node): Promise<SV
     { x: (-3 * h) / 6, y: -h },
   ];
 
-  let polygon: d3.Selection<SVGPolygonElement | SVGGElement, unknown, null, undefined>;
+  let polygon: typeof shapeSvg | ReturnType<typeof insertPolygonShape>;
   const { cssStyles } = node;
 
   if (node.look === 'handDrawn') {
+    // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
     const rc = rough.svg(shapeSvg);
     const options = userNodeOverrides(node, {});
     const pathData = createPathFromPoints(points);
@@ -86,4 +91,4 @@ export const inv_trapezoid = async (parent: SVGAElement, node: Node): Promise<SV
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/labelRect.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/labelRect.ts
index 7aff91902..de53da4f1 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/labelRect.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/labelRect.ts
@@ -2,8 +2,12 @@ import type { Node, RectOptions } from '../../types.js';
 import { drawRect } from './drawRect.js';
 import { labelHelper, updateNodeBounds } from './util.js';
 import intersect from '../intersect/index.js';
+import type { D3Selection } from '../../../types.js';
 
-export const roundedRect = async (parent: SVGAElement, node: Node) => {
+export async function roundedRect<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node
+) {
   const options = {
     rx: 5,
     ry: 5,
@@ -13,9 +17,9 @@ export const roundedRect = async (parent: SVGAElement, node: Node) => {
   } as RectOptions;
 
   return drawRect(parent, node, options);
-};
+}
 
-export const labelRect = async (parent: SVGElement, node: Node) => {
+export async function labelRect<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   const { shapeSvg, bbox, label } = await labelHelper(parent, node, 'label');
 
   // log.trace('Classes = ', node.class);
@@ -52,4 +56,4 @@ export const labelRect = async (parent: SVGElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/leanLeft.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/leanLeft.ts
index 4d03d06e8..03c8b8d3c 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/leanLeft.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/leanLeft.ts
@@ -4,8 +4,9 @@ import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
 import { insertPolygonShape } from './insertPolygonShape.js';
+import type { D3Selection } from '../../../types.js';
 
-export const lean_left = async (parent: SVGAElement, node: Node): Promise<SVGAElement> => {
+export async function lean_left<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const nodePadding = node.padding ?? 0;
@@ -36,10 +37,11 @@ export const lean_left = async (parent: SVGAElement, node: Node): Promise<SVGAEl
     { x: -(3 * h) / 6, y: -h },
   ];
 
-  let polygon: d3.Selection<SVGPolygonElement | SVGGElement, unknown, null, undefined>;
+  let polygon: typeof shapeSvg | ReturnType<typeof insertPolygonShape>;
   const { cssStyles } = node;
 
   if (node.look === 'handDrawn') {
+    // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
     const rc = rough.svg(shapeSvg);
     const options = userNodeOverrides(node, {});
     const pathData = createPathFromPoints(points);
@@ -71,4 +73,4 @@ export const lean_left = async (parent: SVGAElement, node: Node): Promise<SVGAEl
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/leanRight.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/leanRight.ts
index 59d3cb80b..b7e7c1409 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/leanRight.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/leanRight.ts
@@ -4,8 +4,9 @@ import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
 import { insertPolygonShape } from './insertPolygonShape.js';
+import type { D3Selection } from '../../../types.js';
 
-export const lean_right = async (parent: SVGAElement, node: Node): Promise<SVGAElement> => {
+export async function lean_right<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const nodePadding = node.padding ?? 0;
@@ -38,10 +39,11 @@ export const lean_right = async (parent: SVGAElement, node: Node): Promise<SVGAE
     { x: 0, y: -h },
   ];
 
-  let polygon: d3.Selection<SVGPolygonElement | SVGGElement, unknown, null, undefined>;
+  let polygon: typeof shapeSvg | ReturnType<typeof insertPolygonShape>;
   const { cssStyles } = node;
 
   if (node.look === 'handDrawn') {
+    // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
     const rc = rough.svg(shapeSvg);
     const options = userNodeOverrides(node, {});
     const pathData = createPathFromPoints(points);
@@ -72,4 +74,4 @@ export const lean_right = async (parent: SVGAElement, node: Node): Promise<SVGAE
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/lightningBolt.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/lightningBolt.ts
index 17f65e993..90cd9612b 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/lightningBolt.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/lightningBolt.ts
@@ -1,12 +1,13 @@
 import { log } from '../../../logger.js';
-import { createPathFromPoints, getNodeClasses, updateNodeBounds } from './util.js';
-import type { Node } from '../../types.d.ts';
-import type { SVG } from '../../../diagram-api/types.js';
+import { getNodeClasses, updateNodeBounds } from './util.js';
+import type { Node } from '../../types.js';
 import { userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
 import intersect from '../intersect/index.js';
+import { createPathFromPoints } from './util.js';
+import type { D3Selection } from '../../../types.js';
 
-export const lightningBolt = (parent: SVG, node: Node) => {
+export function lightningBolt<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   node.label = '';
   const shapeSvg = parent
     .insert('g')
@@ -58,4 +59,4 @@ export const lightningBolt = (parent: SVG, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/linedCylinder.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/linedCylinder.ts
index 1aa5b3a97..c305ab67a 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/linedCylinder.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/linedCylinder.ts
@@ -3,6 +3,8 @@ import intersect from '../intersect/index.js';
 import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
+import type { D3Selection } from '../../../types.js';
+import { handleUndefinedAttr } from '../../../utils.js';
 
 export const createCylinderPathD = (
   x: number,
@@ -58,7 +60,10 @@ export const createInnerCylinderPathD = (
 const MIN_HEIGHT = 10;
 const MIN_WIDTH = 10;
 
-export const linedCylinder = async (parent: SVGAElement, node: Node) => {
+export async function linedCylinder<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node
+) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const nodePadding = node.padding ?? 0;
@@ -89,10 +94,11 @@ export const linedCylinder = async (parent: SVGAElement, node: Node) => {
   const h = (node?.height ? node?.height : bbox.height) + ry + labelPaddingY;
   const outerOffset = h * 0.1; // 10% of height
 
-  let cylinder: d3.Selection<SVGPathElement | SVGGElement, unknown, null, undefined>;
+  let cylinder: typeof shapeSvg | D3Selection<SVGPathElement>;
   const { cssStyles } = node;
 
   if (node.look === 'handDrawn') {
+    // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
     const rc = rough.svg(shapeSvg);
     const outerPathData = createOuterCylinderPathD(0, 0, w, h, rx, ry, outerOffset);
     const innerPathData = createInnerCylinderPathD(0, ry, w, h, rx, ry);
@@ -114,7 +120,7 @@ export const linedCylinder = async (parent: SVGAElement, node: Node) => {
       .insert('path', ':first-child')
       .attr('d', pathData)
       .attr('class', 'basic label-container')
-      .attr('style', cssStyles)
+      .attr('style', handleUndefinedAttr(cssStyles))
       .attr('style', nodeStyles);
   }
 
@@ -155,4 +161,4 @@ export const linedCylinder = async (parent: SVGAElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/linedWaveEdgedRect.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/linedWaveEdgedRect.ts
index ef2f3c534..e55ffbcac 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/linedWaveEdgedRect.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/linedWaveEdgedRect.ts
@@ -5,11 +5,15 @@ import {
   generateFullSineWavePoints,
 } from './util.js';
 import intersect from '../intersect/index.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import rough from 'roughjs';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
+import type { D3Selection } from '../../../types.js';
 
-export const linedWaveEdgedRect = async (parent: SVGAElement, node: Node) => {
+export async function linedWaveEdgedRect<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node
+) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
 
@@ -37,6 +41,7 @@ export const linedWaveEdgedRect = async (parent: SVGAElement, node: Node) => {
   const finalH = h + waveAmplitude;
   const { cssStyles } = node;
 
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, {});
 
@@ -93,4 +98,4 @@ export const linedWaveEdgedRect = async (parent: SVGAElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/multiRect.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/multiRect.ts
index 036b980e8..58ce7b49e 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/multiRect.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/multiRect.ts
@@ -1,10 +1,11 @@
 import { labelHelper, getNodeClasses, updateNodeBounds, createPathFromPoints } from './util.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
 import intersect from '../intersect/index.js';
+import type { D3Selection } from '../../../types.js';
 
-export const multiRect = async (parent: SVGAElement, node: Node) => {
+export async function multiRect<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const nodePadding = node.padding ?? 0;
@@ -34,6 +35,7 @@ export const multiRect = async (parent: SVGAElement, node: Node) => {
   const y = -h / 2;
   const { cssStyles } = node;
 
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, {});
 
@@ -98,4 +100,4 @@ export const multiRect = async (parent: SVGAElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/multiWaveEdgedRectangle.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/multiWaveEdgedRectangle.ts
index 5dc56667d..04908ddcf 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/multiWaveEdgedRectangle.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/multiWaveEdgedRectangle.ts
@@ -6,11 +6,15 @@ import {
   generateFullSineWavePoints,
 } from './util.js';
 import intersect from '../intersect/index.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import rough from 'roughjs';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
+import type { D3Selection } from '../../../types.js';
 
-export const multiWaveEdgedRectangle = async (parent: SVGAElement, node: Node) => {
+export async function multiWaveEdgedRectangle<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node
+) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const { shapeSvg, bbox, label } = await labelHelper(parent, node, getNodeClasses(node));
@@ -84,6 +88,7 @@ export const multiWaveEdgedRectangle = async (parent: SVGAElement, node: Node) =
     { x, y },
   ];
 
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, {});
 
@@ -126,4 +131,4 @@ export const multiWaveEdgedRectangle = async (parent: SVGAElement, node: Node) =
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/note.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/note.ts
index 926a76749..403294783 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/note.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/note.ts
@@ -3,12 +3,13 @@ import type { Node, ShapeRenderOptions } from '../../types.js';
 import intersect from '../intersect/index.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import { getNodeClasses, labelHelper, updateNodeBounds } from './util.js';
+import type { D3Selection } from '../../../types.js';
 
-export const note = async (
-  parent: SVGAElement,
+export async function note<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
   node: Node,
   { config: { themeVariables } }: ShapeRenderOptions
-) => {
+) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const { shapeSvg, bbox } = await labelHelper(parent, node, getNodeClasses(node));
@@ -55,4 +56,4 @@ export const note = async (
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/question.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/question.ts
index 50e946f95..11d166936 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/question.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/question.ts
@@ -5,6 +5,7 @@ import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
 import { insertPolygonShape } from './insertPolygonShape.js';
+import type { D3Selection } from '../../../types.js';
 
 export const createDecisionBoxPathD = (x: number, y: number, size: number): string => {
   return [
@@ -16,7 +17,7 @@ export const createDecisionBoxPathD = (x: number, y: number, size: number): stri
   ].join(' ');
 };
 
-export const question = async (parent: SVGAElement, node: Node): Promise<SVGAElement> => {
+export async function question<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const padding = (node.padding ?? 0) * 4;
@@ -44,10 +45,11 @@ export const question = async (parent: SVGAElement, node: Node): Promise<SVGAEle
     { x: 0, y: -s / 2 },
   ];
 
-  let polygon: d3.Selection<SVGPolygonElement | SVGGElement, unknown, null, undefined>;
+  let polygon: typeof shapeSvg | ReturnType<typeof insertPolygonShape>;
   const { cssStyles } = node;
 
   if (node.look === 'handDrawn') {
+    // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
     const rc = rough.svg(shapeSvg);
     const options = userNodeOverrides(node, {});
     const pathData = createDecisionBoxPathD(0, 0, s);
@@ -83,4 +85,4 @@ export const question = async (parent: SVGAElement, node: Node): Promise<SVGAEle
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/rectLeftInvArrow.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/rectLeftInvArrow.ts
index 19413f96c..57b739c67 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/rectLeftInvArrow.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/rectLeftInvArrow.ts
@@ -3,11 +3,12 @@ import intersect from '../intersect/index.js';
 import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
+import type { D3Selection } from '../../../types.js';
 
-export const rect_left_inv_arrow = async (
-  parent: SVGAElement,
+export async function rect_left_inv_arrow<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
   node: Node
-): Promise<SVGAElement> => {
+) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const nodePadding = node.padding ?? 0;
@@ -36,6 +37,7 @@ export const rect_left_inv_arrow = async (
   ];
 
   const { cssStyles } = node;
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, {});
 
@@ -71,4 +73,4 @@ export const rect_left_inv_arrow = async (
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/rectWithTitle.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/rectWithTitle.ts
index a71ebabd7..bcaf2787a 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/rectWithTitle.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/rectWithTitle.ts
@@ -9,8 +9,12 @@ import rough from 'roughjs';
 import { getConfig } from '../../../diagram-api/diagramAPI.js';
 import { createRoundedRectPathD } from './roundedRectPath.js';
 import { log } from '../../../logger.js';
+import type { D3Selection } from '../../../types.js';
 
-export const rectWithTitle = async (parent: SVGElement, node: Node) => {
+export async function rectWithTitle<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node
+) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   let classes;
@@ -36,7 +40,7 @@ export const rectWithTitle = async (parent: SVGElement, node: Node) => {
 
   const title = node.label;
 
-  const text = label.node().appendChild(await createLabel(title, node.labelStyle, true, true));
+  const text = label.node()!.appendChild(await createLabel(title, node.labelStyle, true, true));
   let bbox = { width: 0, height: 0 };
   if (evaluate(getConfig()?.flowchart?.htmlLabels)) {
     const div = text.children[0];
@@ -49,7 +53,7 @@ export const rectWithTitle = async (parent: SVGElement, node: Node) => {
   const textRows = description || [];
   const titleBox = text.getBBox();
   const descr = label
-    .node()
+    .node()!
     .appendChild(
       await createLabel(
         textRows.join ? textRows.join('<br/>') : textRows,
@@ -87,7 +91,7 @@ export const rectWithTitle = async (parent: SVGElement, node: Node) => {
   // Get the size of the label
 
   // Bounding box for title and text
-  bbox = label.node().getBBox();
+  bbox = label.node()!.getBBox();
 
   // Center the label
   label.attr(
@@ -151,4 +155,4 @@ export const rectWithTitle = async (parent: SVGElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/roundedRect.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/roundedRect.ts
index e43c00dc0..e2ad53fc5 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/roundedRect.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/roundedRect.ts
@@ -1,7 +1,11 @@
 import type { Node, RectOptions } from '../../types.js';
+import type { D3Selection } from '../../../types.js';
 import { drawRect } from './drawRect.js';
 
-export const roundedRect = async (parent: SVGAElement, node: Node) => {
+export async function roundedRect<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node
+) {
   const nodePadding = node.padding ?? 0;
   const options = {
     rx: node.look === 'neo' ? 3 : 5,
@@ -13,4 +17,4 @@ export const roundedRect = async (parent: SVGAElement, node: Node) => {
   } as RectOptions;
 
   return drawRect(parent, node, options);
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/shadedProcess.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/shadedProcess.ts
index 202447225..43979700f 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/shadedProcess.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/shadedProcess.ts
@@ -1,13 +1,18 @@
 import { labelHelper, updateNodeBounds, getNodeClasses } from './util.js';
 import intersect from '../intersect/index.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
+import type { D3Selection } from '../../../types.js';
+import { handleUndefinedAttr } from '../../../utils.js';
 
 /// Width of the frame on the left of the shape
 const FRAME_WIDTH = 8;
 
-export const shadedProcess = async (parent: SVGAElement, node: Node) => {
+export async function shadedProcess<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node
+) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
 
@@ -33,6 +38,7 @@ export const shadedProcess = async (parent: SVGAElement, node: Node) => {
   const y = -totalHeight / 2;
 
   const { cssStyles } = node;
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, {});
 
@@ -58,7 +64,7 @@ export const shadedProcess = async (parent: SVGAElement, node: Node) => {
 
   const rect = shapeSvg.insert(() => roughNode, ':first-child');
 
-  rect.attr('class', 'basic label-container').attr('style', cssStyles);
+  rect.attr('class', 'basic label-container').attr('style', handleUndefinedAttr(cssStyles));
 
   if (nodeStyles && node.look !== 'handDrawn') {
     rect.selectAll('path').attr('style', nodeStyles);
@@ -75,4 +81,4 @@ export const shadedProcess = async (parent: SVGAElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/slopedRect.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/slopedRect.ts
index ecdd745a6..eb0dd1ce5 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/slopedRect.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/slopedRect.ts
@@ -1,10 +1,11 @@
 import { labelHelper, updateNodeBounds, getNodeClasses, createPathFromPoints } from './util.js';
 import intersect from '../intersect/index.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
+import type { D3Selection } from '../../../types.js';
 
-export const slopedRect = async (parent: SVGAElement, node: Node) => {
+export async function slopedRect<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const nodePadding = node.padding ?? 0;
@@ -32,6 +33,7 @@ export const slopedRect = async (parent: SVGAElement, node: Node) => {
 
   const { cssStyles } = node;
 
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, {});
 
@@ -75,4 +77,4 @@ export const slopedRect = async (parent: SVGAElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/squareRect.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/squareRect.ts
index 5ab8e2833..af72a798f 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/squareRect.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/squareRect.ts
@@ -1,7 +1,8 @@
 import type { Node, RectOptions } from '../../types.js';
+import type { D3Selection } from '../../../types.js';
 import { drawRect } from './drawRect.js';
 
-export const squareRect = async (parent: SVGAElement, node: Node) => {
+export async function squareRect<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   const options = {
     rx: 0,
     ry: 0,
@@ -10,4 +11,4 @@ export const squareRect = async (parent: SVGAElement, node: Node) => {
     labelPaddingY: (node?.padding || 0) * 1,
   } as RectOptions;
   return drawRect(parent, node, options);
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/stadium.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/stadium.ts
index 13e0f33c8..84546c737 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/stadium.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/stadium.ts
@@ -4,6 +4,8 @@ import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
 import { createRoundedRectPathD } from './roundedRectPath.js';
+import type { D3Selection } from '../../../types.js';
+import { handleUndefinedAttr } from '../../../utils.js';
 
 export const createStadiumPathD = (
   x: number,
@@ -50,7 +52,7 @@ export const createStadiumPathD = (
   ].join(' ');
 };
 
-export const stadium = async (parent: SVGAElement, node: Node) => {
+export async function stadium<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const nodePadding = node.padding ?? 0;
@@ -82,6 +84,7 @@ export const stadium = async (parent: SVGAElement, node: Node) => {
   let rect;
   const { cssStyles } = node;
   if (node.look === 'handDrawn') {
+    // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
     const rc = rough.svg(shapeSvg);
     const options = userNodeOverrides(node, {});
 
@@ -89,7 +92,7 @@ export const stadium = async (parent: SVGAElement, node: Node) => {
     const roughNode = rc.path(pathData, options);
 
     rect = shapeSvg.insert(() => roughNode, ':first-child');
-    rect.attr('class', 'basic label-container').attr('style', cssStyles);
+    rect.attr('class', 'basic label-container').attr('style', handleUndefinedAttr(cssStyles));
   } else {
     rect = shapeSvg.insert('rect', ':first-child');
 
@@ -111,4 +114,4 @@ export const stadium = async (parent: SVGAElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/state.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/state.ts
index 566a8a2b4..5ab6aaa61 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/state.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/state.ts
@@ -1,11 +1,12 @@
 import type { Node, RectOptions } from '../../types.js';
+import type { D3Selection } from '../../../types.js';
 import { drawRect } from './drawRect.js';
 
-export const state = async (parent: SVGAElement, node: Node) => {
+export async function state<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   const options = {
     rx: node.look === 'neo' ? 3 : 5,
     ry: node.look === 'neo' ? 3 : 5,
     classes: 'flowchart-node',
   } as RectOptions;
   return drawRect(parent, node, options);
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/stateEnd.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/stateEnd.ts
index 6b2c772df..7accda7c1 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/stateEnd.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/stateEnd.ts
@@ -1,15 +1,15 @@
 import rough from 'roughjs';
-import type { SVG } from '../../../diagram-api/types.js';
 import type { Node, ShapeRenderOptions } from '../../types.js';
 import intersect from '../intersect/index.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import { updateNodeBounds } from './util.js';
+import type { D3Selection } from '../../../types.js';
 
-export const stateEnd = (
-  parent: SVG,
+export function stateEnd<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
   node: Node,
   { config: { themeVariables } }: ShapeRenderOptions
-) => {
+) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const { cssStyles } = node;
@@ -83,4 +83,4 @@ export const stateEnd = (
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/stateStart.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/stateStart.ts
index 8f15e3bc7..6d433d10b 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/stateStart.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/stateStart.ts
@@ -1,15 +1,15 @@
 import rough from 'roughjs';
-import type { SVG } from '../../../diagram-api/types.js';
 import type { Node, ShapeRenderOptions } from '../../types.js';
 import intersect from '../intersect/index.js';
 import { solidStateFill } from './handDrawnShapeStyles.js';
 import { updateNodeBounds } from './util.js';
+import type { D3Selection } from '../../../types.js';
 
-export const stateStart = (
-  parent: SVG,
+export function stateStart<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
   node: Node,
   { config: { themeVariables } }: ShapeRenderOptions
-) => {
+) {
   const { lineColor } = themeVariables;
 
   // If incoming height & width are present, subtract the padding from them
@@ -39,25 +39,29 @@ export const stateStart = (
     .attr('class', 'node default')
     .attr('id', node.domId || node.id);
 
-  let circle: d3.Selection<SVGCircleElement, unknown, Element | null, unknown>;
+  let circle: D3Selection<SVGCircleElement> | D3Selection<SVGGElement>;
   if (node.look === 'handDrawn') {
     // @ts-ignore TODO: Fix rough typings
     const rc = rough.svg(shapeSvg);
     const roughNode = rc.circle(0, 0, node.width, solidStateFill(lineColor));
     // @ts-ignore TODO: Fix typings
     circle = shapeSvg.insert(() => roughNode);
+    // center the circle around its coordinate
+    circle
+      .attr('class', 'state-start')
+      .attr('r', (node.width ?? 7) / 2)
+      .attr('width', node.width ?? 14)
+      .attr('height', node.height ?? 14);
   } else {
     circle = shapeSvg.insert('circle', ':first-child');
+    // center the circle around its coordinate
+    circle
+      .attr('class', 'state-start')
+      .attr('r', (node.width ?? 7) / 2)
+      .attr('width', node.width ?? 14)
+      .attr('height', node.height ?? 14);
   }
 
-  // center the circle around its coordinate
-  // @ts-ignore TODO: Fix typings
-  circle
-    .attr('class', 'state-start')
-    .attr('r', (node.width ?? 7) / 2)
-    .attr('width', node.width ?? 14)
-    .attr('height', node.height ?? 14);
-
   updateNodeBounds(node, circle);
 
   node.intersect = function (point) {
@@ -65,4 +69,4 @@ export const stateStart = (
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/subroutine.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/subroutine.ts
index 2f125d5da..1c123c5c4 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/subroutine.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/subroutine.ts
@@ -5,6 +5,8 @@ import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
 import { insertPolygonShape } from './insertPolygonShape.js';
 import { getConfig } from '../../../config.js';
+import type { D3Selection } from '../../../types.js';
+import { handleUndefinedAttr } from '../../../utils.js';
 
 export const createSubroutinePathD = (
   x: number,
@@ -35,7 +37,7 @@ export const createSubroutinePathD = (
 // width of the frame on the left and right side of the shape
 const FRAME_WIDTH = 8;
 
-export const subroutine = async (parent: SVGAElement, node: Node) => {
+export async function subroutine<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   const { themeVariables } = getConfig();
   const { useGradient } = themeVariables;
   const { labelStyles, nodeStyles } = styles2String(node);
@@ -78,6 +80,7 @@ export const subroutine = async (parent: SVGAElement, node: Node) => {
   ];
 
   if (node.look === 'handDrawn' || (node.look === 'neo' && !useGradient)) {
+    // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
     const rc = rough.svg(shapeSvg);
     const options = userNodeOverrides(node, {});
 
@@ -96,7 +99,7 @@ export const subroutine = async (parent: SVGAElement, node: Node) => {
     l2El.attr('class', 'neo-line');
     const rect = shapeSvg.insert(() => roughNode, ':first-child');
     const { cssStyles } = node;
-    rect.attr('class', 'basic label-container').attr('style', cssStyles);
+    rect.attr('class', 'basic label-container').attr('style', handleUndefinedAttr(cssStyles));
     updateNodeBounds(node, rect);
   } else {
     const el = insertPolygonShape(shapeSvg, w, h, points);
@@ -111,4 +114,4 @@ export const subroutine = async (parent: SVGAElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/taggedRect.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/taggedRect.ts
index 03fc9ee6c..86cf87de0 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/taggedRect.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/taggedRect.ts
@@ -1,13 +1,14 @@
 import { labelHelper, getNodeClasses, updateNodeBounds, createPathFromPoints } from './util.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
 import intersect from '../intersect/index.js';
+import type { D3Selection } from '../../../types.js';
 
 /// The width/height of the tag in comparison to the height of the node
 const TAG_RATIO = 0.2;
 
-export const taggedRect = async (parent: SVGAElement, node: Node) => {
+export async function taggedRect<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
 
@@ -41,6 +42,7 @@ export const taggedRect = async (parent: SVGAElement, node: Node) => {
 
   const { cssStyles } = node;
 
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, {});
 
@@ -90,4 +92,4 @@ export const taggedRect = async (parent: SVGAElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/taggedWaveEdgedRectangle.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/taggedWaveEdgedRectangle.ts
index 1947adab9..2dfab77a9 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/taggedWaveEdgedRectangle.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/taggedWaveEdgedRectangle.ts
@@ -6,11 +6,15 @@ import {
   createPathFromPoints,
 } from './util.js';
 import intersect from '../intersect/index.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import rough from 'roughjs';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
+import type { D3Selection } from '../../../types.js';
 
-export const taggedWaveEdgedRectangle = async (parent: SVGAElement, node: Node) => {
+export async function taggedWaveEdgedRectangle<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node
+) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
 
@@ -46,6 +50,7 @@ export const taggedWaveEdgedRectangle = async (parent: SVGAElement, node: Node)
   const widthDif = minWidth - w;
   const extraW = widthDif > 0 ? widthDif / 2 : 0;
 
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, {});
 
@@ -120,4 +125,4 @@ export const taggedWaveEdgedRectangle = async (parent: SVGAElement, node: Node)
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/text.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/text.ts
index 0a0bc4026..397c99b8b 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/text.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/text.ts
@@ -1,9 +1,10 @@
 import { labelHelper, updateNodeBounds, getNodeClasses } from './util.js';
 import intersect from '../intersect/index.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import { styles2String } from './handDrawnShapeStyles.js';
+import type { D3Selection } from '../../../types.js';
 
-export async function text(parent: SVGAElement, node: Node): Promise<SVGAElement> {
+export async function text<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
 
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/tiltedCylinder.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/tiltedCylinder.ts
index 64da61bbf..364a1dc0d 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/tiltedCylinder.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/tiltedCylinder.ts
@@ -1,8 +1,10 @@
 import { labelHelper, getNodeClasses, updateNodeBounds } from './util.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
 import intersect from '../intersect/index.js';
+import type { D3Selection } from '../../../types.js';
+import { handleUndefinedAttr } from '../../../utils.js';
 
 export const createCylinderPathD = (
   x: number,
@@ -52,7 +54,10 @@ export const createInnerCylinderPathD = (
 const MIN_HEIGHT = 5;
 const MIN_WIDTH = 10;
 
-export const tiltedCylinder = async (parent: SVGAElement, node: Node) => {
+export async function tiltedCylinder<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node
+) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const nodePadding = node.padding ?? 0;
@@ -80,9 +85,10 @@ export const tiltedCylinder = async (parent: SVGAElement, node: Node) => {
   const w = (node.width ? node.width : bbox.width) + rx + labelPadding;
   const { cssStyles } = node;
 
-  let cylinder: d3.Selection<SVGPathElement | SVGGElement, unknown, null, undefined>;
+  let cylinder: D3Selection<SVGGElement> | D3Selection<SVGPathElement>;
 
   if (node.look === 'handDrawn') {
+    // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
     const rc = rough.svg(shapeSvg);
     const outerPathData = createOuterCylinderPathD(0, 0, w, h, rx, ry);
     const innerPathData = createInnerCylinderPathD(0, 0, w, h, rx, ry);
@@ -100,19 +106,19 @@ export const tiltedCylinder = async (parent: SVGAElement, node: Node) => {
       .insert('path', ':first-child')
       .attr('d', pathData)
       .attr('class', 'basic label-container')
-      .attr('style', cssStyles)
+      .attr('style', handleUndefinedAttr(cssStyles))
       .attr('style', nodeStyles);
+    cylinder.attr('class', 'basic label-container');
+
+    if (cssStyles) {
+      cylinder.selectAll('path').attr('style', cssStyles);
+    }
+
+    if (nodeStyles) {
+      cylinder.selectAll('path').attr('style', nodeStyles);
+    }
   }
 
-  cylinder.attr('class', 'basic label-container');
-
-  if (cssStyles && node.look !== 'handDrawn') {
-    cylinder.selectAll('path').attr('style', cssStyles);
-  }
-
-  if (nodeStyles && node.look !== 'handDrawn') {
-    cylinder.selectAll('path').attr('style', nodeStyles);
-  }
   cylinder.attr('label-offset-x', rx);
   cylinder.attr('transform', `translate(${-w / 2}, ${h / 2} )`);
 
@@ -149,4 +155,4 @@ export const tiltedCylinder = async (parent: SVGAElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/trapezoid.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/trapezoid.ts
index a41258e14..eee46096c 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/trapezoid.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/trapezoid.ts
@@ -4,6 +4,7 @@ import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
 import { insertPolygonShape } from './insertPolygonShape.js';
+import type { D3Selection } from '../../../types.js';
 
 // export const createTrapezoidPathD = (
 //   x: number,
@@ -20,7 +21,7 @@ import { insertPolygonShape } from './insertPolygonShape.js';
 //   ].join(' ');
 // };
 
-export const trapezoid = async (parent: SVGAElement, node: Node): Promise<SVGAElement> => {
+export async function trapezoid<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const nodePadding = node.padding ?? 0;
@@ -51,10 +52,11 @@ export const trapezoid = async (parent: SVGAElement, node: Node): Promise<SVGAEl
     { x: 0, y: -h },
   ];
 
-  let polygon: d3.Selection<SVGPolygonElement | SVGGElement, unknown, null, undefined>;
+  let polygon: typeof shapeSvg | ReturnType<typeof insertPolygonShape>;
   const { cssStyles } = node;
 
   if (node.look === 'handDrawn') {
+    // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
     const rc = rough.svg(shapeSvg);
     const options = userNodeOverrides(node, {});
     const pathData = createPathFromPoints(points);
@@ -85,4 +87,4 @@ export const trapezoid = async (parent: SVGAElement, node: Node): Promise<SVGAEl
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/trapezoidalPentagon.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/trapezoidalPentagon.ts
index 292ba2889..14d8d55c8 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/trapezoidalPentagon.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/trapezoidalPentagon.ts
@@ -1,10 +1,14 @@
 import { labelHelper, updateNodeBounds, getNodeClasses, createPathFromPoints } from './util.js';
 import intersect from '../intersect/index.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
+import type { D3Selection } from '../../../types.js';
 
-export const trapezoidalPentagon = async (parent: SVGAElement, node: Node) => {
+export async function trapezoidalPentagon<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node
+) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const nodePadding = node.padding ?? 0;
@@ -31,6 +35,7 @@ export const trapezoidalPentagon = async (parent: SVGAElement, node: Node) => {
     (node?.height ? node?.height : Math.max(minHeight, bbox.height)) + (labelPaddingY ?? 0) * 2;
 
   const { cssStyles } = node;
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, {});
 
@@ -70,4 +75,4 @@ export const trapezoidalPentagon = async (parent: SVGAElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/triangle.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/triangle.ts
index 2ef8db1e4..09603744c 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/triangle.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/triangle.ts
@@ -1,17 +1,18 @@
 import { log } from '../../../logger.js';
 import { labelHelper, updateNodeBounds, getNodeClasses } from './util.js';
 import intersect from '../intersect/index.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
 import { createPathFromPoints } from './util.js';
 import { evaluate } from '../../../diagrams/common/common.js';
 import { getConfig } from '../../../diagram-api/diagramAPI.js';
+import type { D3Selection } from '../../../types.js';
 
 const MIN_HEIGHT = 10;
 const MIN_WIDTH = 10;
 
-export const triangle = async (parent: SVGAElement, node: Node): Promise<SVGAElement> => {
+export async function triangle<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const nodePadding = node.padding ?? 0;
@@ -40,6 +41,7 @@ export const triangle = async (parent: SVGAElement, node: Node): Promise<SVGAEle
 
   const { cssStyles } = node;
 
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, {});
   if (node.look !== 'handDrawn') {
@@ -77,4 +79,4 @@ export const triangle = async (parent: SVGAElement, node: Node): Promise<SVGAEle
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/util.js b/packages/mermaid/src/rendering-util/rendering-elements/shapes/util.ts
similarity index 68%
rename from packages/mermaid/src/rendering-util/rendering-elements/shapes/util.js
rename to packages/mermaid/src/rendering-util/rendering-elements/shapes/util.ts
index 5abeab476..92c9b2199 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/util.js
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/util.ts
@@ -1,13 +1,20 @@
 import { createText } from '../../createText.js';
+import type { Node } from '../../types.js';
 import { getConfig } from '../../../diagram-api/diagramAPI.js';
 import { select } from 'd3';
+import defaultConfig from '../../../defaultConfig.js';
 import { evaluate, sanitizeText } from '../../../diagrams/common/common.js';
-import { decodeEntities } from '../../../utils.js';
 import { log } from '../../../logger.js';
+import { decodeEntities, handleUndefinedAttr, parseFontSize } from '../../../utils.js';
+import type { D3Selection, Point } from '../../../types.js';
 
-export const labelHelper = async (parent, node, _classes) => {
+export const labelHelper = async <T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node,
+  _classes?: string
+) => {
   let cssClasses;
-  const useHtmlLabels = node.useHtmlLabels || evaluate(getConfig().flowchart.htmlLabels);
+  const useHtmlLabels = node.useHtmlLabels || evaluate(getConfig()?.flowchart?.htmlLabels);
   if (!_classes) {
     cssClasses = 'node default';
   } else {
@@ -21,7 +28,10 @@ export const labelHelper = async (parent, node, _classes) => {
     .attr('id', node.domId || node.id);
 
   // Create the label and insert it after the rect
-  const labelEl = shapeSvg.insert('g').attr('class', 'label').attr('style', node.labelStyle);
+  const labelEl = shapeSvg
+    .insert('g')
+    .attr('class', 'label')
+    .attr('style', handleUndefinedAttr(node.labelStyle));
 
   // Replace label with default value if undefined
   let label;
@@ -31,19 +41,19 @@ export const labelHelper = async (parent, node, _classes) => {
     label = typeof node.label === 'string' ? node.label : node.label[0];
   }
 
-  let text;
-  text = await createText(labelEl, sanitizeText(decodeEntities(label), getConfig()), {
+  const text = await createText(labelEl, sanitizeText(decodeEntities(label), getConfig()), {
     useHtmlLabels,
-    width: node.width < 0 ? 0 : node.width || getConfig().flowchart.wrappingWidth,
+    width: (node.width ?? 0) < 0 ? 0 : node.width || getConfig().flowchart?.wrappingWidth,
+    // @ts-expect-error -- This is currently not used. Should this be `classes` instead?
     cssClasses: 'markdown-node-label',
     style: node.labelStyle,
     addSvgBackground: !!node.icon || !!node.img,
   });
   // Get the size of the label
   let bbox = text.getBBox();
-  const halfPadding = node.padding / 2;
+  const halfPadding = (node?.padding ?? 0) / 2;
 
-  if (evaluate(getConfig().flowchart.htmlLabels)) {
+  if (evaluate(getConfig().flowchart?.htmlLabels)) {
     const div = text.children[0];
     const dv = select(text);
 
@@ -69,7 +79,8 @@ export const labelHelper = async (parent, node, _classes) => {
                     ? getConfig().fontSize
                     : window.getComputedStyle(document.body).fontSize;
                   const enlargingFactor = 5;
-                  const width = parseInt(bodyFontSize, 10) * enlargingFactor + 'px';
+                  const [parsedBodyFontSize = defaultConfig.fontSize] = parseFontSize(bodyFontSize);
+                  const width = parsedBodyFontSize * enlargingFactor + 'px';
                   img.style.minWidth = width;
                   img.style.maxWidth = width;
                 } else {
@@ -109,8 +120,12 @@ export const labelHelper = async (parent, node, _classes) => {
   return { shapeSvg, bbox, halfPadding, label: labelEl };
 };
 
-export const updateNodeBounds = (node, element) => {
-  const bbox = element.node().getBBox();
+export const updateNodeBounds = <T extends SVGGraphicsElement>(
+  node: Node,
+  // D3Selection<SVGGElement> is for the roughjs case, D3Selection<T> is for the non-roughjs case
+  element: D3Selection<SVGGElement> | D3Selection<T>
+) => {
+  const bbox = element.node()!.getBBox();
   node.width = bbox.width;
   node.height = bbox.height;
   log.debug('updateNodeBounds: #####################################');
@@ -119,12 +134,17 @@ export const updateNodeBounds = (node, element) => {
 };
 
 /**
- * @param parent
- * @param w
- * @param h
- * @param points
+ * @param parent - Parent element to append the polygon to
+ * @param w - Width of the polygon
+ * @param h - Height of the polygon
+ * @param points - Array of points to create the polygon
  */
-export function insertPolygonShape(parent, w, h, points) {
+export function insertPolygonShape(
+  parent: D3Selection<SVGGElement>,
+  w: number,
+  h: number,
+  points: Point[]
+) {
   return parent
     .insert('polygon', ':first-child')
     .attr(
@@ -139,16 +159,23 @@ export function insertPolygonShape(parent, w, h, points) {
     .attr('transform', 'translate(' + -w / 2 + ',' + h / 2 + ')');
 }
 
-export const getNodeClasses = (node, extra) =>
+export const getNodeClasses = (node: Node, extra?: string) =>
   (node.look === 'handDrawn' ? 'rough-node' : 'node') + ' ' + node.cssClasses + ' ' + (extra || '');
 
-export function createPathFromPoints(points) {
+export function createPathFromPoints(points: Point[]) {
   const pointStrings = points.map((p, i) => `${i === 0 ? 'M' : 'L'}${p.x},${p.y}`);
   pointStrings.push('Z');
   return pointStrings.join(' ');
 }
 
-export function generateFullSineWavePoints(x1, y1, x2, y2, amplitude, numCycles) {
+export function generateFullSineWavePoints(
+  x1: number,
+  y1: number,
+  x2: number,
+  y2: number,
+  amplitude: number,
+  numCycles: number
+) {
   const points = [];
   const steps = 50; // Number of segments to create a smooth curve
   const deltaX = x2 - x1;
@@ -170,13 +197,21 @@ export function generateFullSineWavePoints(x1, y1, x2, y2, amplitude, numCycles)
   return points;
 }
 
+/**
+ * @param centerX - x-coordinate of center of circle
+ * @param centerY - y-coordinate of center of circle
+ * @param radius - radius of circle
+ * @param numPoints - total points required
+ * @param startAngle - angle where arc will start
+ * @param endAngle - angle where arc will end
+ */
 export function generateCirclePoints(
-  centerX, // x-coordinate of center of circle
-  centerY, // x-coordinate of center of circle
-  radius, // radius of circle
-  numPoints, // total points required
-  startAngle, //  angle where arc will start
-  endAngle // angle where arc will end
+  centerX: number,
+  centerY: number,
+  radius: number,
+  numPoints: number,
+  startAngle: number,
+  endAngle: number
 ) {
   const points = [];
 
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/waveEdgedRectangle.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/waveEdgedRectangle.ts
index 58c481af6..ab3217d3e 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/waveEdgedRectangle.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/waveEdgedRectangle.ts
@@ -6,11 +6,15 @@ import {
   createPathFromPoints,
 } from './util.js';
 import intersect from '../intersect/index.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import rough from 'roughjs';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
+import type { D3Selection } from '../../../types.js';
 
-export const waveEdgedRectangle = async (parent: SVGAElement, node: Node) => {
+export async function waveEdgedRectangle<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node
+) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
 
@@ -44,6 +48,7 @@ export const waveEdgedRectangle = async (parent: SVGAElement, node: Node) => {
   const widthDif = minWidth - w;
   const extraW = widthDif > 0 ? widthDif / 2 : 0;
 
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, {});
 
@@ -94,4 +99,4 @@ export const waveEdgedRectangle = async (parent: SVGAElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/waveRectangle.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/waveRectangle.ts
index 9ed2ef592..ceadd1503 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/waveRectangle.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/waveRectangle.ts
@@ -6,11 +6,15 @@ import {
   generateFullSineWavePoints,
 } from './util.js';
 import intersect from '../intersect/index.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
+import type { D3Selection } from '../../../types.js';
 
-export const waveRectangle = async (parent: SVGAElement, node: Node) => {
+export async function waveRectangle<T extends SVGGraphicsElement>(
+  parent: D3Selection<T>,
+  node: Node
+) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
   const nodePadding = node.padding ?? 0;
@@ -43,6 +47,7 @@ export const waveRectangle = async (parent: SVGAElement, node: Node) => {
   const finalH = h + waveAmplitude * 2;
   const { cssStyles } = node;
 
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, {});
 
@@ -83,4 +88,4 @@ export const waveRectangle = async (parent: SVGAElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/windowPane.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/windowPane.ts
index d4da0d228..2abb85346 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/windowPane.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/windowPane.ts
@@ -1,13 +1,14 @@
 import { labelHelper, getNodeClasses, updateNodeBounds } from './util.js';
-import type { Node } from '../../types.ts';
+import type { Node } from '../../types.js';
 import { styles2String, userNodeOverrides } from './handDrawnShapeStyles.js';
 import rough from 'roughjs';
 import intersect from '../intersect/index.js';
+import type { D3Selection } from '../../../types.js';
 
 /// Width of the frame on the top and left of the shape
 const rectOffset = 5;
 
-export const windowPane = async (parent: SVGAElement, node: Node) => {
+export async function windowPane<T extends SVGGraphicsElement>(parent: D3Selection<T>, node: Node) {
   const { labelStyles, nodeStyles } = styles2String(node);
   node.labelStyle = labelStyles;
 
@@ -34,6 +35,7 @@ export const windowPane = async (parent: SVGAElement, node: Node) => {
   const y = -h / 2;
   const { cssStyles } = node;
 
+  // @ts-expect-error -- Passing a D3.Selection seems to work for some reason
   const rc = rough.svg(shapeSvg);
   const options = userNodeOverrides(node, {});
 
@@ -81,4 +83,4 @@ export const windowPane = async (parent: SVGAElement, node: Node) => {
   };
 
   return shapeSvg;
-};
+}
diff --git a/packages/mermaid/src/rendering-util/types.ts b/packages/mermaid/src/rendering-util/types.ts
index 5c6be4877..776347f75 100644
--- a/packages/mermaid/src/rendering-util/types.ts
+++ b/packages/mermaid/src/rendering-util/types.ts
@@ -147,5 +147,6 @@ export type LayoutMethod =
 
 export interface ShapeRenderOptions {
   config: MermaidConfig;
-  dir: string;
+  /** Some shapes render differently if a diagram has a direction `LR` */
+  dir?: Node['dir'];
 }
diff --git a/packages/mermaid/src/types.ts b/packages/mermaid/src/types.ts
index c26130bf5..196773e6a 100644
--- a/packages/mermaid/src/types.ts
+++ b/packages/mermaid/src/types.ts
@@ -79,6 +79,11 @@ export interface ParseResult {
 // This makes it clear that we're working with a d3 selected element of some kind, even though it's hard to specify the exact type.
 export type D3Element = any;
 
+/**
+ * Helper type for d3 selections.
+ */
+export type D3Selection<T extends SVGElement> = d3.Selection<T, unknown, Element | null, unknown>;
+
 export interface RenderResult {
   /**
    * The svg code for the rendered graph.
@@ -99,3 +104,10 @@ export interface RenderResult {
    */
   bindFunctions?: (element: Element) => void;
 }
+
+/**
+ * Can be converted back to `T` by awaiting/`Awaited<T>`.
+ *
+ * This is useful for function types that may be either synchronous or asynchronous.
+ */
+export type MaybePromise<T> = T | Promise<T>;
diff --git a/packages/mermaid/src/utils.ts b/packages/mermaid/src/utils.ts
index 631b6dd85..f523197ae 100644
--- a/packages/mermaid/src/utils.ts
+++ b/packages/mermaid/src/utils.ts
@@ -1,5 +1,5 @@
 import { sanitizeUrl } from '@braintree/sanitize-url';
-import type { CurveFactory } from 'd3';
+import type { BaseType, CurveFactory } from 'd3';
 import {
   curveBasis,
   curveBasisClosed,
@@ -940,3 +940,15 @@ export const getEdgeId = (
 ) => {
   return `${prefix ? `${prefix}_` : ''}${from}_${to}_${counter}${suffix ? `_${suffix}` : ''}`;
 };
+
+/**
+ * D3's `selection.attr` method doesn't officially support `undefined`.
+ *
+ * However, it seems if you do pass `undefined`, it seems to be treated as `null`
+ * (e.g. it removes the attribute).
+ */
+export function handleUndefinedAttr(
+  attrValue: Parameters<d3.Selection<BaseType, unknown, HTMLElement, any>['attr']>[1] | undefined
+) {
+  return attrValue ?? null;
+}