[Page Builder Plugin Siteorigin] help in responsive theme

Hi I am using page builder plugin by site origin in my website and I use twenty twelve responsive theme and I use two column in page content area but problem is that when I open it on mobile or small screen both widget area or the columns shrinks and saw both in one page but I want that when we open in small screen it show under first widget.i have problem in these page if you like u can visit https://www.upschub.com/mains/