Changing a few things profile CSS

Hey guys. So I've been toying around with the free editable layout by Lazy + trying out tips from Tetra's CSS guide, and I've gotten quite a bit down... but there's some stuff I've been trying to fix all day and I'm getting worn out ;_; Anyone mind helping?

1. How do I get rid of those white lines on the side? I changed the borders, but those seem to be like... within the border? I don'd understand what it is and why it's doing that.

2. The white outlines on the profile and den thing. I changed the border color again, but it didn't work. So I'm assuming it's something else?

3. How do I change the layout of tables in my description at all? I can't find them anywhere to edit and I'm like, SUPER new to this. I'd like to change the background color of the tables.

Thanks for the help!