Fix Space port (7860) and theme placement

app.py

@@ -189,7 +189,7 @@ def run_inference(
 # ── UI ─────────────────────────────────────────────────────────────────────────
 
 def build_ui():
-    with gr.Blocks(title="PanCancerSeg Inference") as demo:
+    with gr.Blocks(title="PanCancerSeg Inference", theme=gr.themes.Soft()) as demo:
         gr.Markdown(
             """
 # PanCancerSeg — Specialist CT Tumour Segmentation
@@ -260,5 +260,10 @@ a segmentation mask and visualisations.
 
 
 if __name__ == "__main__":
+    import os
+
     demo = build_ui()
-    demo.launch( server_name="0.0.0.0", server_port=7869, share=False, theme=gr.themes.Soft())
+    # Hugging Face Spaces expect the app on port 7860 (set via GRADIO_SERVER_PORT).
+    # Locally this falls back to 7860 unless overridden.
+    port = int(os.environ.get("GRADIO_SERVER_PORT", 7860))
+    demo.launch(server_name="0.0.0.0", server_port=port, share=False)