Center thumbnail gallery in AutoFocus

This is my first post, so I am sorry if this is in the wrong location!

I’m trying to center my gallery of thumbnails as seen on…

https://www.chrisbavaria.com/wordpress/?p=371

I am using AutoFocus Lite. I figured out how to center the text in the css but can’t seem to figure out how to do the all of the thumbnails.

Any help is much appreciated!