Center nav bar & reduce responsive menu width

Hi, I want to center the menu navigation bar (true center) on my page, and also reduce the width before the navigation turns into its responsive form.

I did a ton of searching, but most solutions were for the older versions of customizr. I also am completely lost and don’t really know what I’m doing. Please help.

http://fadula.com ;; yes, I am using a child theme with style.css and function.php. Not sure where and how to approach this issue with the new version of customizr.