Plugin “breaks” Checkout Page (theming)

Hello!

I have just taken over a site that was designed and built by someone else using the Divi Builder. My client wants to add Gift Cards and I’ve activated this plugin, and set up my “product” and everything works, except that the plugin somehow overrides our theme settings.

When you add a gift card or any other item from the store and go to checkout, the buttons have lost all of our theme customization and the checkout button itself is now white and therefore hidden to the customer.

When I disable the plugin, everything goes back to normal. Is this something that I can fix with custom CSS? I would appreciate ANY help I can get on this issue. I’m still just learning the ropes on this site and am not writing my own CSS.

Thanks!