Mobile Nav Toggle Hidden

Hello! I’ve searched through as much as I can on the forums regarding similar issues, but I’m sure you have an easy patch ready to throw up here. My mobile nav toggle is not showing up for this site – http://cheek-law.com/

I did try adding this CSS under the general styling tab:

#advanced_menu_toggle, #advanced_menu_hide {
background-color: #ffffff;
color: #719430;
border-color: #719430;
}

But it was to no avail. Please help. Thanks!