How to change forumhome so that it'll show a "chain" of depth?

[DataHero]

Well after some extensive searching, etc. I've managed to find how to increase the depth display: I had to add a forumhome_forumbit_level3_nopost/post and had to copypaste the contents of the level2_nopost/post accordingly.

As said, it shows the way I wanted now, except one thing. I'd like to indent the subforums to the right a bit more, so it's better to see which are subforums, and which are not (see attachment). Any idea how I'd go on about that?