Centered design for LearnCenter?

Content

I am redesigning our LearnCenter and would like to center all information in the middle of the page to match our other corporate internal sites. Kind of like how this page is centered instead of left-aligned. But that sidebar is making it impossible for me to do this, and I can't put some CSS in the header, leave a <div> open, and then close the </div> in each individual page. My header is centered just fine (at a fixed width of 1024px) but if I do the same with the body of the home  page, it is shifted over to