Apply SR app's proven background CSS approach

Use exact same CSS as SR app which has consistent background:
- body { background: #fafafa \!important; }
- .gradio-container { background-color: #fafafa \!important; }

This matches the working SR implementation instead of trying experimental approaches.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

app.py

@@ -139,14 +139,13 @@ with gr.Blocks(
     theme=gr.themes.Default(),
     title="MobileNetV2 Classification",
     css="""
-    html, body, .gradio-app {
-        background: white !important;
-        background-color: white !important;
+    body {
+        background: #fafafa !important;
     }
     .gradio-container {
         max-width: 1200px !important;
         margin: auto !important;
-        background-color: white !important;
+        background-color: #fafafa !important;
         font-family: 'Inter', 'Segoe UI', -apple-system, sans-serif !important;
     }
     .main-header {