Update app.py

app.py

@@ -107,7 +107,7 @@ def log_to_csv_and_push(user_id, level, passage, question, user_answer, correct,
         "user_answer": user_answer,
         "correct": correct,
         "response_time": response_time,
-        "timestamp": [(datetime.utcnow() + timedelta(hours=9)).strftime("%Y-%m-%d %H:%M:%S")],
+        "timestamp": (datetime.utcnow() + timedelta(hours=9)).strftime("%Y-%m-%d %H:%M:%S"),
     }
 
     # --- ローカルに追記 ---