diff --git a/src/api/blackboard_routes.py b/src/api/blackboard_routes.py
index 511e982..cad2fcd 100644
--- a/src/api/blackboard_routes.py
+++ b/src/api/blackboard_routes.py
@@ -13,21 +13,17 @@ from src.blackboard.models import Task, Review
 from src.blackboard.queries import Queries
 from src.blackboard.db import VALID_STATUSES, VALID_TRANSITIONS, COMMENT_TYPES, OUTPUT_TYPES
 
+from src.utils import get_data_root
+
 router = APIRouter(prefix="/api/projects/{project_id}", tags=["blackboard"])
 
 
 def _bb(project_id: str) -> Blackboard:
-    import os
-    root = Path(os.environ.get("BLACKBOARD_ROOT",
-        str(Path.home() / ".sanguo_projects" / "sanguo_moziplus_v2" / "projects")))
-    return Blackboard(root / project_id / "blackboard.db")
+    return Blackboard(get_data_root() / project_id / "blackboard.db")
 
 
 def _q(project_id: str) -> Queries:
-    import os
-    root = Path(os.environ.get("BLACKBOARD_ROOT",
-        str(Path.home() / ".sanguo_projects" / "sanguo_moziplus_v2" / "projects")))
-    return Queries(root / project_id / "blackboard.db")
+    return Queries(get_data_root() / project_id / "blackboard.db")
 
 
 # --- Tasks ---