Host broke my site

Recently my web host cancelled my account by accident. It was reinstated a few hours later but in the process they broke my site: the menu was rearranged, my widgets disappeared, a random post was changed (maybe more, I haven't checked them all), and the pale grey border that surrounds the main text reappeared. My site is a child theme of Catch Box. According to what I can see, the child theme is active. Yet I have managed to fix everything except get rid of the border. I have gone through all my child theme's modifications, but cannot for the life of me figure this out. Can you please tell me where in the theme files the grey border is located so that I can fix this. For reference, my site is www.mademers.com. Any help is much appreciated.