diff --git a/frontend/src/components/simulator/CircuitVerificationModal.tsx b/frontend/src/components/simulator/CircuitVerificationModal.tsx
index 3deddafb..bd1a75ff 100644
--- a/frontend/src/components/simulator/CircuitVerificationModal.tsx
+++ b/frontend/src/components/simulator/CircuitVerificationModal.tsx
@@ -78,7 +78,8 @@ const styles: Record<string, React.CSSProperties> = {
     display: 'flex',
     alignItems: 'center',
     justifyContent: 'center',
-    zIndex: 1000,
+    // Above the agent side panel (z 8000): a modal is always the top task.
+    zIndex: 9000,
   },
   modal: {
     background: '#252526',
diff --git a/frontend/src/components/simulator/InstallLibrariesModal.css b/frontend/src/components/simulator/InstallLibrariesModal.css
index eb0a8d54..8acffa0c 100644
--- a/frontend/src/components/simulator/InstallLibrariesModal.css
+++ b/frontend/src/components/simulator/InstallLibrariesModal.css
@@ -5,7 +5,8 @@
   display: flex;
   align-items: center;
   justify-content: center;
-  z-index: 1100;
+  /* Above the agent side panel (z 8000): a modal is always the top task. */
+  z-index: 9000;
   backdrop-filter: blur(4px);
   animation: ilib-fadeIn 0.15s ease;
 }
diff --git a/frontend/src/components/simulator/LibraryManagerModal.css b/frontend/src/components/simulator/LibraryManagerModal.css
index e88db751..e91ff882 100644
--- a/frontend/src/components/simulator/LibraryManagerModal.css
+++ b/frontend/src/components/simulator/LibraryManagerModal.css
@@ -6,7 +6,8 @@
   display: flex;
   align-items: center;
   justify-content: center;
-  z-index: 1000;
+  /* Above the agent side panel (z 8000): a modal is always the top task. */
+  z-index: 9000;
   backdrop-filter: blur(4px);
   animation: lib-fadeIn 0.15s ease;
 }