Remove borders from toolbar and status bar

Is there someone know how to remove the borders from Toolbar and Statusbar? I have setted the border to none, but it seems don’t work.

They may be borders from the Main application window areas. Don’t know if you can change those.

Check the documentation.

I asked chatgpt and try to set the qss it given to me. And then I found that the border is not the QToolbar’s border, and also not the QMainWindow’s Separator. It may be created by the Windows Style of QT. I must set the Qstyle to Fusion or other styles to remove the borders, but it seems need to edit the source code.