Centering

Hey guys.

I’m having a little bit of difficulty with my new WP blog. Running the latest version with the 3 column Marketplace theme.

I’m not 100% sure how to put this into words here, but… when I expand my web browser horizontally, the header appears to center itself no matter how wide the web browser gets. This is fine, but the content table below it does not center itself, it sits anchored.

I’d prefer if they both centered themselves automatically based on how wide the users web browser is. How do i do this?

You can look at what I’m talking about at: https://www.driplab.com

I appreciate any help!

Thanks!