diff --git a/apps/worker/video_processing/transition_engine.py b/apps/worker/video_processing/transition_engine.py
index 3cab0a26f..03b8409ff 100755
--- a/apps/worker/video_processing/transition_engine.py
+++ b/apps/worker/video_processing/transition_engine.py
@@ -23,6 +23,7 @@ else:
     class StrEnum(str, Enum):
         pass
 
+
 from video_processing.ffmpeg_utils import build_xfade_filter_chain
 
 logger = logging.getLogger(__name__)
diff --git a/tests/unit/test_transition_engine.py b/tests/unit/test_transition_engine.py
index 545a9dcc0..a41a9a92f 100755
--- a/tests/unit/test_transition_engine.py
+++ b/tests/unit/test_transition_engine.py
@@ -3,7 +3,6 @@
 from __future__ import annotations
 
 import pytest
-
 from video_processing.transition_engine import (
     CUT_TRANSITION,
     DEFAULT_TRANSITION_DURATION,
@@ -15,7 +14,6 @@ from video_processing.transition_engine import (
     _normalize_transition_name,
 )
 
-
 # ── TransitionType 枚举测试 ──────────────────────────────────────────────────
 
 
@@ -293,9 +291,7 @@ class TestTransitionEngine:
     def test_resolve_clip_transitions_all_valid(self):
         """批量解析全部有效转场."""
         engine = TransitionEngine()
-        configs = engine.resolve_clip_transitions(
-            ["cut", "fade", "dissolve", "slideleft"]
-        )
+        configs = engine.resolve_clip_transitions(["cut", "fade", "dissolve", "slideleft"])
         assert len(configs) == 4
         assert configs[0].effect == "cut"
         assert configs[0].is_cut is True
@@ -306,9 +302,7 @@ class TestTransitionEngine:
     def test_resolve_clip_transitions_with_fallback(self):
         """批量解析包含不支持的转场，自动降级."""
         engine = TransitionEngine()
-        configs = engine.resolve_clip_transitions(
-            ["fade", "bad_effect", "dissolve", "worse_effect"]
-        )
+        configs = engine.resolve_clip_transitions(["fade", "bad_effect", "dissolve", "worse_effect"])
         assert len(configs) == 4
         assert configs[0].effect == "fade"
         assert configs[1].effect == "cut"  # 降级