Is there any documentation on the Forum styles?

It's taking me a very long time to identify which class in CMSForums.css belongs to what. Sometimes it's reasonably clear what the class would be applied to, but other times not. eg, I'm trying to remove the background colour from forum posts, and have a thin line between them. If I modify the background-color: in ForumPost it is applied, but if I add border-bottom: black solid; it is ignored.

There's also some padding on the outer left/right edges which I'm trying to remove. Somehow (without knowing how I did it) I managed to remove the padding for the right side of the posts page but not the left, and on the Forum lists page there is still about 1px padding that I can't remove.

It's a frustrating trial-n-error game.

Regards,
Sharon