Update app.py

app.py

@@ -1,17 +1,17 @@
 import panel as pn
 
 # Create a Panel app with centered title
-title = pn.pane.HTML("<h1 style='text-align: center;'>My Panel App</h1>", width_policy='max', height_policy='max')
+title = pn.pane.HTML("<h1 style='text-align: center;'>My Panel App</h1>", width=300)
 
 # Create a toggleable sidebar with three horizontal lines icon
 toggle_sidebar = pn.widgets.Button(name='☰', button_type='primary', width=30, height=30)
 toggle_sidebar.js_on_click(args={'sidebar': toggle_sidebar}, code="""
     if (sidebar.width == 0) {
         sidebar.width = 200;
-        buttons.visible = True;
+        buttons.css_classes = ['visible'];
     } else {
         sidebar.width = 0;
-        buttons.visible = False;
+        buttons.css_classes = ['hidden'];
     }
 """)
 
@@ -21,7 +21,7 @@ button2 = pn.widgets.Button(name='Button 2')
 button3 = pn.widgets.Button(name='Button 3')
 
 # Create a column layout for the buttons inside the toggleable sidebar
-buttons = pn.Column(button1, button2, button3, visible=False, sizing_mode='stretch_height', background='#f6f6f6')
+buttons = pn.Column(button1, button2, button3, sizing_mode='stretch_height', background='#f6f6f6', css_classes=['hidden'])
 
 # Combine the title, toggle button, and sidebar
 app = pn.Column(
@@ -31,9 +31,10 @@ app = pn.Column(
         pn.layout.Divider(),
         pn.Row(buttons, sizing_mode='stretch_width'),
         sizing_mode='stretch_both',
+        align='center',
     ),
     sizing_mode='stretch_both',
 )
 
 # Run the app
-app.servable()
+app.servable()