Remove menu for one page

I am attempting to remove a menu on specific pages.

http://salonweb.io/courses/salon-web-free

This code works but it's removing ot for the entire site. I only want to remove it for one page.
#floating_menu {
display: none;
}

I tried this but it's not working... page ID 11 is a custom post type.
.page-id-11 #floating_menu{
display: none;
}

Any advise?