Update app.py

app.py

@@ -102,6 +102,20 @@ css = """
 
 with gr.Blocks(theme='xiaobaiyuan/theme_demo') as demo:
 
+        with gr.Column(scale=3):
+            with gr.Box():
+                dropdown.render()
+                toggle_dark = gr.Button(value="Toggle Dark").style(full_width=True)
+
+    dropdown.change(None, dropdown, None, _js=js)
+    toggle_dark.click(
+        None,
+        _js="""
+        () => {
+            document.body.classList.toggle('dark');
+        }
+        """,
+    )
 
     with gr.Row():
         with gr.Column(scale=6):