I'm using an old, old version of shrinking/centering, because I can't be bothered to upgrade as long as whatever new stuff LJ decides to implement doesn't break my layout.
My archaic function page_layout is here, all viewable and junk.
[ETA] I should add that my reason for asking is because it'd be nifty to be able to reproduce the nav bar underneath the entries.
[ETA2] Solved. Thanks, kunzite1!