I have the same issue. I think it's the fluid engine causing the extra space, which may be why there isn't a styling-based (CSS) solution. When I inspect my pages, there is no indication of a margin or a padding on the element. I can change the max-height, but that just makes the space above less and the space below more.
My suggestion is to play with layering of your elements in the editor and make use of the "move forward/backward" and "align vertically" features. In that way you can still see the text but keep the functionality of the accordion. Then, if the elements are too crammed looking, you can add additional padding to make them look right. Good luck!