Scaling site on mobile

Hi, love the theme, but have noticed I am having issues with mobile.
My site is
I use a special gallery format for my images that is 553 pixels wide. For some reason the code meant to scale everything down for mobile was breaking images in vertical format, so I removed the css that scaled the images. Now, of course, the images “break out” of the text box in mobile, because they are not scaling. How would I create a rule for the scaling for mobile, that nothing will be scaled smaller than 553 pixels? That way everything will look like it fits in the text box, and the mobile browser will accommodate?