This theme comes with several page templates available that offer different layout options. Furthermore there is the ability to create your own using the core layout feature; however you can only set the desktop grid here and not specifically set for mobile.

If you need more flexibility then you may need to create your own 'page template' with custom code. We can not support this type of modification but you can view some great documentation here -http://foundation.zurb.com/docs/components/grid.html....

Thanks