Apply research-based fix: Use SR's exact margin pattern

Research findings:
- SR uses margin-left/right: auto (54 \!important declarations)
- Our demos used margin: 0 auto (97-119 \!important declarations)
- Issue: CSS conflicts between heavy custom styling and Gradio's layout system

Solution: Match SR's proven margin pattern exactly to avoid layout conflicts.

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

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

app.py

@@ -144,7 +144,8 @@ with gr.Blocks(
     }
     .gradio-container {
         max-width: 1200px !important;
-        margin: 0 auto !important;
+        margin-left: auto !important;
+        margin-right: auto !important;
         background-color: #fafafa !important;
         font-family: 'Inter', 'Segoe UI', -apple-system, sans-serif !important;
     }