Can’t format

I used this on this page;

https://piedmontcardiovascular.com/patient-information/faqs/
and I like the gradient background for the questions.

I’m redesigning the site on a new theme, installed this but now the questions are a flat black.

https://piedmontcardiovascular.com/temp/patient-information/faqs/

I can’t find any way to change to the gradient. I copied the css onto my stylesheet, but it’s being overridden. In the page editor for either page, there’s no control over the FAQ block.