diff --git a/packages/mermaid/src/diagrams/flowchart/flowDb.ts b/packages/mermaid/src/diagrams/flowchart/flowDb.ts
index a0beeaa8c..aee427069 100644
--- a/packages/mermaid/src/diagrams/flowchart/flowDb.ts
+++ b/packages/mermaid/src/diagrams/flowchart/flowDb.ts
@@ -818,6 +818,10 @@ const addNodeFromVertex = (
       linkTarget: vertex.linkTarget,
       tooltip: getTooltip(vertex.id),
     });
+  } else {
+    node.cssStyles = vertex.styles;
+    node.cssCompiledStyles = getCompiledStyles(vertex.classes);
+    node.cssClasses = vertex.classes.join(' ');
   }
 };
 
@@ -827,10 +831,10 @@ function getCompiledStyles(classDefs: string[]) {
     const cssClass = classes.get(customClass);
     if (cssClass) {
       if (cssClass.styles) {
-        compiledStyles = [...compiledStyles, ...(cssClass.styles ?? [])];
+        compiledStyles = [...compiledStyles, ...(cssClass.styles ?? [])].map((s) => s.trim());
       }
       if (cssClass.textStyles) {
-        compiledStyles = [...compiledStyles, ...(cssClass.textStyles ?? [])];
+        compiledStyles = [...compiledStyles, ...(cssClass.textStyles ?? [])].map((s) => s.trim());
       }
     }
   }
@@ -866,8 +870,8 @@ export const getData = () => {
       labelStyle: '',
       parentId: parentDB.get(subGraph.id),
       padding: config.flowchart?.padding || 8,
-      cssStyles: [],
-      cssClasses: '',
+      cssCompiledStyles: getCompiledStyles(subGraph.classes),
+      cssClasses: subGraph.classes.join(' '),
       shape: 'rect',
       dir: subGraph.dir,
       isGroup: true,
@@ -902,6 +906,8 @@ export const getData = () => {
     edges.push(edge);
   });
 
+  log.debug('IPI nodes', JSON.stringify(nodes, null, 2));
+
   return { nodes, edges, other: {}, config };
 };
 
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/clusters.js b/packages/mermaid/src/rendering-util/rendering-elements/clusters.js
index 23de549e6..58e3dec07 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/clusters.js
+++ b/packages/mermaid/src/rendering-util/rendering-elements/clusters.js
@@ -8,7 +8,10 @@ import { createText } from '../createText.ts';
 import intersectRect from '../rendering-elements/intersect/intersect-rect.js';
 import createLabel from './createLabel.js';
 import { createRoundedRectPathD } from './shapes/roundedRectPath.ts';
-import { userNodeOverrides } from '$root/rendering-util/rendering-elements/shapes/handdrawnStyles.js';
+import {
+  styles2String,
+  userNodeOverrides,
+} from '$root/rendering-util/rendering-elements/shapes/handdrawnStyles.js';
 
 const rect = async (parent, node) => {
   log.info('Creating subgraph rect for ', node.id, node);
@@ -16,13 +19,18 @@ const rect = async (parent, node) => {
   const { themeVariables, handdrawnSeed } = siteConfig;
   const { clusterBkg, clusterBorder } = themeVariables;
 
+  const { labelStyles, nodeStyles } = styles2String(node);
+
   // Add outer g element
-  const shapeSvg = parent.insert('g').attr('class', 'cluster').attr('id', node.id);
+  const shapeSvg = parent
+    .insert('g')
+    .attr('class', 'cluster ' + node.cssClasses)
+    .attr('id', node.id);
 
   const useHtmlLabels = evaluate(siteConfig.flowchart.htmlLabels);
 
   // Create the label and insert it after the rect
-  const labelEl = shapeSvg.insert('g').attr('class', 'cluster-label');
+  const labelEl = shapeSvg.insert('g').attr('class', 'cluster-label ');
 
   // const text = label
   //   .node()
@@ -82,7 +90,7 @@ const rect = async (parent, node) => {
     rect = shapeSvg.insert('rect', ':first-child');
     // center the rect around its coordinate
     rect
-      .attr('style', node.cssStyles)
+      .attr('style', nodeStyles)
       .attr('rx', node.rx)
       .attr('ry', node.ry)
       .attr('x', x)
@@ -104,6 +112,13 @@ const rect = async (parent, node) => {
       `translate(${node.x}, ${node.y - node.height / 2 + subGraphTitleTopMargin})`
     );
   }
+
+  if (labelStyles) {
+    const span = labelEl.select('span');
+    if (span) {
+      span.attr('style', labelStyles);
+    }
+  }
   // Center the label
 
   const rectBox = rect.node().getBBox();