diff --git a/agent-team/agent_team/nodes/handbook.py b/agent-team/agent_team/nodes/handbook.py
index 5141298..39ae7cf 100644
--- a/agent-team/agent_team/nodes/handbook.py
+++ b/agent-team/agent_team/nodes/handbook.py
@@ -69,7 +69,9 @@ def load_handbook_conventions(path: Optional[Path | str] = None) -> str:
         sections: list[str] = []
         for fpath in files:
             try:
-                raw = fpath.read_bytes()[:_MAX_FILE_BYTES].decode("utf-8", errors="replace")
+                raw = fpath.read_bytes()[:_MAX_FILE_BYTES].decode(
+                    "utf-8", errors="replace"
+                )
                 sections.append(f"### {fpath.stem}\n{raw.strip()}")
             except Exception:  # noqa: BLE001 - safe no-op
                 continue