fix: move CSS to launch, add demo.launch

app.py

@@ -280,7 +280,7 @@ CSS = """
 .gradio-container {max-width: 1200px !important;}
 """
 
-with gr.Blocks(css=CSS, title="Terrain Diffusion Demo") as demo:
+with gr.Blocks(title="Terrain Diffusion Demo") as demo:
     gr.Markdown("# 🏔️ Terrain Diffusion Demo")
     gr.Markdown(
         "Generate realistic terrain heightmaps using the "
@@ -377,4 +377,4 @@ with gr.Blocks(css=CSS, title="Terrain Diffusion Demo") as demo:
         outputs=[relief_output, elev_output, preview_3d_output, download_output, cond_output, stats_output],
     )
 
-demo = demo
+demo.launch(css=CSS)