Re: Child div not applying parent div border.
Alright, so I've managed to get this fixed. As it turns out, the problem was not with my CSS so much as it was with my HTML. The problem was not with my floats, it was with the height of my wrapper. I removed the height of the wrapper and allowed it to stretch to fit content (this was originally set to help me see things better during development).
All in all, the problem was solved, I appreciate all effort by those of you who posted. (I'll remember about the z-axis in the future).
If it's hard, you're doing it wrong.