diff --git a/frontend/src/components/FileExplorer.tsx b/frontend/src/components/FileExplorer.tsx
index a378b5f..4d2e8e8 100644
--- a/frontend/src/components/FileExplorer.tsx
+++ b/frontend/src/components/FileExplorer.tsx
@@ -195,6 +195,7 @@ export default function FileExplorer({ onLogout }: FileExplorerProps) {
 
   useEffect(() => {
     const handlePopState = (e: PopStateEvent) => {
+      setEditingFile(null);
       if (e.state && e.state.path) setCurrentPath(e.state.path);
       else setCurrentPath(new URLSearchParams(window.location.search).get('path') || '.');
       setPreviewFile(null);
@@ -208,6 +209,11 @@ export default function FileExplorer({ onLogout }: FileExplorerProps) {
   const [viewMode, setViewMode] = useState<ViewMode>('grid');
   const [appMode, setAppMode] = useState<'drive' | 'docs' | 'slides' | 'sheets'>('drive');
   const [editingFile, setEditingFile] = useState<FileItem | null>(null);
+
+  const openEditor = useCallback((file: FileItem) => {
+    setEditingFile(file);
+    window.history.pushState({ editing: true, path: currentPath }, '', window.location.search || window.location.href);
+  }, [currentPath]);
   const [activeSection, setActiveSection] = useState<SidebarSection>('files');
   const [searchQuery, setSearchQuery] = useState('');
   const [searchResults, setSearchResults] = useState<FileItem[] | null>(null);
@@ -531,13 +537,13 @@ export default function FileExplorer({ onLogout }: FileExplorerProps) {
         navigateToFolder(file);
       } else if (file.name.endsWith('.docx')) {
         setAppMode('docs');
-        setEditingFile(file);
+        openEditor(file);
       } else if (file.name.endsWith('.pptx')) {
         setAppMode('slides');
-        setEditingFile(file);
+        openEditor(file);
       } else if (file.name.endsWith('.xlsx') || file.name.endsWith('.xls')) {
         setAppMode('sheets');
-        setEditingFile(file);
+        openEditor(file);
       } else {
         setPreviewFile(file);
       }
@@ -1929,9 +1935,9 @@ export default function FileExplorer({ onLogout }: FileExplorerProps) {
         ) : (appMode === 'docs' || appMode === 'slides' || appMode === 'sheets') && activeSection === 'files' ? (
           <OfficeHome 
             type={appMode} 
-            onFileSelect={(file) => setEditingFile(file)} 
+            onFileSelect={(file) => openEditor(file)} 
             onCreateBlank={(file) => {
-              setEditingFile(file);
+              openEditor(file);
               loadFiles();
             }}
             onPinChange={() => setPinnedRefreshCounter(c => c + 1)}