How do I get the theme to content area to center for smaller monitors?

I LOVE this theme. It’s the best theme ever. It’s the theme I’ve been looking for.

I have one question and I’m pretty sure I’ll never have another one.
I have made the template fixed 1440px, it’s perfect!
My problem is, when people with old monitors visit, they see the left side - 2 left side bars and the content area.
I would like them to see the 2 inner side bars (inner left and inner right side bars) and the middle content area. The outer side bars will need to be scrolled too to see them.

How do I get the theme to center so the content area is always in the middle no matter what monitor a visitor is using?

Thank you! Thank you!

(V. Atahualpa 3.5.3)