How to remove the logo from the mobile version as it is now shows on the top ban

Hi All,

I am using KAMI theme. When you open mobile the logo comes over the top header
my site is techbel3arabi.com
Any help with that?
I found some CSS like:
@media only screen and (max-width:460px){
img#site-logo {
display:none;
}
}

but never works!