style: 简化文档卡片样式，优化布局间距

backend/tts_asr.py

@@ -197,8 +197,9 @@ class ASRResponse(BaseModel):
 
 
 def get_api_key(api_key: str):
-    from backend.main import API_KEY
+    import main
 
+    API_KEY = main.API_KEY
     if api_key != API_KEY:
         raise HTTPException(status_code=403, detail="API Key 无效")
     return api_key