Proteo button styles

Dear Support,

Is there a way for me to edit the css styles directly of the buttons in Proteo theme? I can go to the Customise Menu and change the look of the buttons there, but when I name a button with a class or an ID, and try to address that specifically in the CSS, the only button property that changes is the font size. I would like to edit the length, the bg color the hover color as well. The reason for this is that I have embedded a mailchimp form and I want to change the “submit” button property by addressing the css class in the html, but when I add custom css to the button ID or button Class – no changes occur.

Any advice for me?
Thank you so much!
Eunice

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