fixed z-index issue

frontend/src/components/Constructor/CanvasElement.tsx

@@ -21,6 +21,7 @@ import type { CanvasElement as CanvasElementType } from '../../types/constructor
 import type { ResolvedTransitionSettings } from '../../types/transition';
 import type { PreloadCacheProvider } from '../../hooks/video';
 import { isInfoPanelElementType } from '../../lib/elementDefaults';
+import { normalizeZIndexValue } from '../../lib/elementStyles';
 
 interface CanvasElementProps {
   element: CanvasElementType;
@@ -136,6 +137,10 @@ const CanvasElement: React.FC<CanvasElementProps> = ({
     top: `${yClamped}%`,
     transform: 'translate(-50%, -50%)',
   };
+  const zIndex = normalizeZIndexValue(element.zIndex);
+  if (zIndex !== undefined) {
+    positionStyle.zIndex = zIndex;
+  }
 
   // Add appear animation to outer div (ALWAYS - for WYSIWYG)
   // Animation is applied to outer div to keep positioning hack working

frontend/src/components/RuntimeElement.tsx

@@ -20,6 +20,7 @@ import type { CanvasElement } from '../types/constructor';
 import type { ResolvedTransitionSettings } from '../types/transition';
 import type { PreloadCacheProvider } from '../hooks/video';
 import { isInfoPanelElementType } from '../lib/elementDefaults';
+import { normalizeZIndexValue } from '../lib/elementStyles';
 
 interface RuntimeElementProps {
   element: CanvasElement;
@@ -115,6 +116,10 @@ const RuntimeElement: React.FC<RuntimeElementProps> = ({
     transform: `translate(-50%, -50%)${rotation ? ` rotate(${rotation}deg)` : ''}`,
     pointerEvents: 'auto',
   };
+  const zIndex = normalizeZIndexValue(element.zIndex);
+  if (zIndex !== undefined) {
+    positionStyle.zIndex = zIndex;
+  }
 
   // Add appear animation to outer div
   // Animation stays on outer div to keep positioning hack working

frontend/src/lib/elementStyles.ts

@@ -267,6 +267,16 @@ const getTrimmedValue = (value: unknown): string => {
   return String(value).trim();
 };
 
+export const normalizeZIndexValue = (
+  value: unknown,
+): CSSProperties['zIndex'] | undefined => {
+  const zIndexValue = getTrimmedValue(value);
+  if (!zIndexValue) return undefined;
+
+  const parsed = Number(zIndexValue);
+  return Number.isFinite(parsed) ? parsed : undefined;
+};
+
 /**
  * Build React CSSProperties from element style properties.
  * Handles type coercion for special properties like opacity and zIndex.
@@ -326,13 +336,8 @@ export function buildElementStyle(
   }
 
   // Handle zIndex (needs numeric conversion, already in style from loop but override with number)
-  const zIndexValue = getTrimmedValue(source.zIndex);
+  const zIndex = normalizeZIndexValue(source.zIndex);
-  if (zIndexValue) {
+  if (zIndex !== undefined) style.zIndex = zIndex;
-    const parsed = Number(zIndexValue);
-    if (Number.isFinite(parsed)) {
-      style.zIndex = parsed;
-    }
-  }
 
   return style;
 }