Catch Box on mobile devices

Hello! I am using Catch Box theme for this website www.bruceselinrealestate.com The problem is theme's poor performance on mobile devices such as smart phones. You can also test it by re-sizing your browser, make it much smaller. The menu should become drop down menu as it is here for example  http://catchthemes.com/demo/catchbox/ I am still using version 1.0.7, I could probably solve this problem by updating the theme, but I did a lot of customization and do not really want to do it again...I hope somebody knows how to solve this problem adding some piece of code. Any help is very appreciated! Thank you, Vasily