SS 7.0 Flatiron Template - main content does not fill live screen

I’m using SS 7.0 “flatiron” template. The main page content is not filling the screen when live. It fills the screen in the editor, but on the live pages and galleries. It justifies the left side of the screen/content area. In the styles section, there is a slider that reads “project detail width” with a max of 1200pix. I need the entire page to be responsive and fill the screen. You'll notice, in the live view, there is a lot of empty realestate to the right of the main image (see attached examples).

Can the width be a percentage rather than a fixed pixel width? 

Can this change be made in the code? Custom CSS? 

9 hours ago, Finalshot said:

In the styles section, there is a slider that reads “project detail width” with a max of 1200pix

Have you tried adjusting this to be larger? That should solve this for you.

Hi, thanks Ziggy.  I saw that, it's at 1600 so that must be its limit.  Thank you for the help!