mobile menu disappearing

Hello, I have a problem. On mobile devices and at reduced window size on PC's, the menus first break into two lines (under 1161px), then simply disappear (under 961px). It happens with all three menus (only two of them are active). The site address is: http://www.hellokonyv.hu/ I also would like to know if there is a way to switch off both side widgets in under a certain screen resolution.