Hello,
1. We have 3 types of buttons on our site – light (for example http://prntscr.com/hdcwhy), dark (for example http://prntscr.com/hdcwxi), active (for example http://prntscr.com/hdcx3r). You may use Theme Options > Styling -> Content > Customize buttons to change styles of your buttons.
2. Theme Options > Typography > Navigation > Menu 1 level hover (active) + you may delete this custom css code http://prntscr.com/jbxbkn
Regards