Site width

I was playing around my header.php, and I’m not sure what I changed but my site content and sidebar are now very wide filling up the entire space. I used to have some white space around the main content and my sidebar on the left and right sides of the page, but now there is none. How can I fix this so I have some margin/padding around my content and sidebar? The rest of the site is fine (header, footer, nav bar) the way it is now so I do not want to change that.

Here’s my site: http://whatgreatgrandmaate.com/