Q:

How to hide elements in mobile devices? CSS

I want to hide this sidebar in mobile devices, I tried this coding, 
.sidebar__area:last-child .widget:last-child, .sidebar__area.is_stuck .widget:last-child{
display:none;
}

Which completely hid it.But when I try this, it doesn't work,
@media screen and (min-device-width: 100px) and (max-device-width: 950px{
sidebar__area:last-child .widget:last-child, .sidebar__area.is_stuck .widget:last-child{
    display:none;
    }

A:

Try this:
@media (min-width: 100px) and (max-width: 950px){
sidebar__area:last-child .widget:last-child, .sidebar__area.is_stuck .widget:last-child{
    display:none;
    }

