Fix

text.py

@@ -24,4 +24,7 @@ class SimpleCLITool(App):
         # Dock the TabbedContent into the app's view
         await self.view.dock(tabbed_content)
 
-SimpleCLITool.run()
+# Create an instance of the app and run it
+if __name__ == "__main__":
+    app = SimpleCLITool()
+    app.run()