How to disable default style which is appended when we upload html code in Eloqua?

Hello Everyone,

I am facing an issue with the landing page where Eloqua inserts its own style when I try to upload the HTML code into the editor. However, I tried multiple times by removing those but unfortunately, iI cannot able to remove that.

This affects my CSS style which i wrote externally.

Can anyone say me how i can remove that pre-existing style which Eloqua inserts into code?

Thanks!!