How to edit ZD styling for elements?

Hello,

I'm trying to remove the bottom margin for lists, but only for when they appear in the important (green box) call-out. I've tried editing the style.css file but there seems to be a zd-article class that I can't find in the stylesheet so I don't know where it's coded. I tried overriding it in style.css, but it doesn't work.

Hope someone can help me on this. Thank you!