diff --git a/backend/app/main.py b/backend/app/main.py
index 1bbd1f5..6cb4c6f 100644
--- a/backend/app/main.py
+++ b/backend/app/main.py
@@ -1,8 +1,9 @@
 from contextlib import asynccontextmanager
 from pathlib import Path
 
-from fastapi import FastAPI
+from fastapi import FastAPI, HTTPException
 from fastapi.middleware.cors import CORSMiddleware
+from fastapi.responses import FileResponse
 from fastapi.staticfiles import StaticFiles
 from sqlalchemy import select
 
@@ -67,7 +68,25 @@ def create_app() -> FastAPI:
 
     frontend_dist = ROOT / "frontend" / "dist"
     if frontend_dist.is_dir():
-        app.mount("/", StaticFiles(directory=str(frontend_dist), html=True), name="ui")
+        assets_dir = frontend_dist / "assets"
+        if assets_dir.is_dir():
+            app.mount(
+                "/assets",
+                StaticFiles(directory=str(assets_dir)),
+                name="ui-assets",
+            )
+
+        @app.get("/{spa_path:path}")
+        def spa_fallback(spa_path: str) -> FileResponse:
+            if spa_path.startswith("api/"):
+                raise HTTPException(status_code=404, detail="Not Found")
+            candidate = frontend_dist / spa_path
+            if spa_path and candidate.is_file():
+                return FileResponse(candidate)
+            index = frontend_dist / "index.html"
+            if not index.is_file():
+                raise HTTPException(status_code=404, detail="UI not built")
+            return FileResponse(index)
 
     return app