Update app.py

app.py

@@ -80,6 +80,12 @@ app = gr.Interface(
     fn=swap_face, 
     title="Welcome to Roop!", 
     theme='JohnSmith9982/small_and_pretty', 
+    _js="""
+        () => {
+            document.body.classList.toggle('dark');
+            document.querySelector('gradio-app').style.backgroundColor = 'var(--color-background-primary)'
+        }
+        """, 
     inputs=[
         gr.Image(label="Source Image:"), 
         gr.Image(label="Target Image:"),