Some pages fixed and some stretchy?

I can't quite get the look I want. I started with the Pixie template, which has a fixed width design. I like that look on my home page and folders page (and a few other pages I will be developing which are primarily text).

However, my galleries will primarily be in smugmug style, and I really need those to be stretchy (fill the available width).

I have a common header (title and menu) and footer that are on the "Entire Site". My problem is that I can't find a way to make the "galleries" page stretchy without making "Entire Site" stretchy. That sort of works...and I can go to my folders page and other pages and make them fixed width, but the shared items (title/menu, for example) still stretch. So those pages don't look quite as nice. I could make each page custom, but that would involve recreating the menu on every page.

Does anybody know of an easy way to accomplish this? I haven't published my new site yet so I've attached a couple of screen shots below.

Here's what I'd like:


And here's what I end up with if I make "Entire Site" stretchy, which I've done in order to get the galleries page stretchy (note the Title & menu way off to the sides). I didn't bother to put margins on them...but that's not really the issue...


I can live with it, but was hoping for a better solution...