Fix HF unstyled UI: disable SSR, stop pip-overriding Gradio

Gradio 5 SSR on Spaces often serves plain HTML without CSS when Node
is unavailable. Pin sdk_version 5.23.0 and remove gradio from
requirements.txt so HF's bundled frontend matches the server.

Co-authored-by: Cursor <cursoragent@cursor.com>

README.md

@@ -4,7 +4,7 @@ emoji: 🔬
 colorFrom: blue
 colorTo: green
 sdk: gradio
-sdk_version: "5.16.1"
+sdk_version: "5.23.0"
 python_version: "3.10"
 app_file: app.py
 pinned: false

app.py

@@ -6,6 +6,9 @@ import os
 import socket
 from pathlib import Path
 
+# HF Spaces: SSR needs Node and often serves unstyled HTML when it fails.
+os.environ.setdefault("GRADIO_SSR_MODE", "false")
+
 _ROOT = Path(__file__).resolve().parent
 
 
@@ -20,8 +23,6 @@ def _configure_runtime() -> None:
     )
     if _is_hf_space():
         os.environ.setdefault("PRELOAD_MODEL", "1")
-        # Do NOT set GRADIO_SERVER_NAME here — HF injects GRADIO_ROOT_PATH; forcing
-        # 0.0.0.0 breaks CSS/JS (unstyled black-and-white page behind the proxy).
 
 
 _configure_runtime()
@@ -146,18 +147,22 @@ def _local_launch_kwargs() -> dict:
     }
 
 
-if __name__ == "__main__":
-    print(f"[RefDiffNet] gradio {getattr(gr, '__version__', 'unknown')}")
-    if os.environ.get("PRELOAD_MODEL", "0").lower() in ("1", "true", "yes"):
-        _preload_model()
-
+def _launch() -> None:
+    """Launch with SSR off (required for themed UI on HF Spaces)."""
+    kwargs: dict = {"show_error": True, "ssr_mode": False}
     if _is_hf_space():
-        # HF Spaces proxy sets PORT + GRADIO_ROOT_PATH — plain launch keeps themed UI.
-        demo.launch(show_error=True)
+        demo.launch(**kwargs)
     else:
         demo.launch(
             **_local_launch_kwargs(),
-            show_error=True,
             inbrowser=False,
             prevent_thread_lock=False,
+            **kwargs,
         )
+
+
+if __name__ == "__main__":
+    print(f"[RefDiffNet] gradio {getattr(gr, '__version__', 'unknown')} ssr_mode=False")
+    if os.environ.get("PRELOAD_MODEL", "0").lower() in ("1", "true", "yes"):
+        _preload_model()
+    _launch()

requirements.txt

@@ -1,4 +1,4 @@
-# Gradio version matches README sdk_version (Hugging Face Spaces)
+# ML deps only — Gradio version is installed by HF from README sdk_version (do not pin here).
 # Python 3.13+ removed stdlib audioop; pydub (gradio dep) needs this backport
 audioop-lts>=0.2.1; python_version >= "3.13"
 torch>=2.0.0
@@ -6,6 +6,4 @@ torchvision>=0.15.0
 pillow>=10.0.0,<11
 # torch 2.2.x wheels are built against NumPy 1.x
 numpy>=1.23.0,<2
-gradio==5.16.1
-gradio-client==1.7.0
 huggingface_hub>=0.23.0,<1.0

run.sh

@@ -0,0 +1,59 @@
+#!/usr/bin/env bash
+# Launch RefDiffNet demo (lightweight: skip reinstall if deps OK)
+set -euo pipefail
+cd "$(dirname "$0")"
+
+if [[ -f "${HOME}/anaconda3/etc/profile.d/conda.sh" ]]; then
+  # shellcheck source=/dev/null
+  source "${HOME}/anaconda3/etc/profile.d/conda.sh"
+  conda activate pcb
+fi
+
+PY="${CONDA_PREFIX:-}/bin/python"
+PIP="${CONDA_PREFIX:-}/bin/pip"
+SITE="${CONDA_PREFIX:-}/lib/python3.10/site-packages"
+
+echo "==> Python: $(which python)"
+
+need_numpy_fix() {
+  ! "${PY}" -c "import numpy; assert numpy.__version__.startswith('1.')" 2>/dev/null
+}
+
+fix_numpy() {
+  echo "==> numpy 1.x (torch 2.2)"
+  if ! "${PIP}" install --no-cache-dir --ignore-installed "numpy>=1.23.0,<2" 2>/dev/null; then
+    rm -rf "${SITE}"/numpy "${SITE}"/numpy-*.dist-info 2>/dev/null || true
+    "${PIP}" install --no-cache-dir "numpy>=1.23.0,<2"
+  fi
+}
+
+need_gradio_fix() {
+  ! "${PY}" -c "import gradio_patch; gradio_patch.apply(); import gradio" 2>/dev/null
+}
+
+fix_gradio() {
+  echo "==> gradio 5.23.0 (match HF sdk_version)"
+  "${PIP}" install --no-cache-dir "gradio==5.23.0"
+}
+
+free_port() {
+  local p="$1"
+  if lsof -i:"${p}" -sTCP:LISTEN -t >/dev/null 2>&1; then
+    echo "    Stopping process on port ${p}..."
+    kill "$(lsof -t -i:"${p}" -sTCP:LISTEN 2>/dev/null)" 2>/dev/null || true
+    sleep 1
+  fi
+}
+
+need_numpy_fix && fix_numpy
+need_gradio_fix && fix_gradio
+free_port 7860
+
+export PYTHONNOUSERSITE=1
+export PREBACKBONE_ONLY_WEIGHTS="${PREBACKBONE_ONLY_WEIGHTS:-weights/prebackbone_a11_ca.pt}"
+export PRELOAD_MODEL="${PRELOAD_MODEL:-0}"
+export GRADIO_SHARE="${GRADIO_SHARE:-0}"
+# Low RAM: PREBACKBONE_DEVICE=cpu bash run.sh
+
+echo "==> Starting app (PRELOAD_MODEL=${PRELOAD_MODEL} GRADIO_SHARE=${GRADIO_SHARE})"
+exec "${PY}" app.py