Checking browser using just CSS?

Question

Is it possible to check browsers just with CSS?

I have this code and it seems to work, it applies the .browser-warning when the browser is IE 10-11.

I need to check if the browser is Safari in a similar way.

// ie10 and Ie11 only
_:-ms-lang(x), 
.browser-warning {
    display: block !important;
}


.browser-warning {
    z-index:999;
    background-color: $gray-400;
    height: 50px;
    text-align: center;
    padding-top: 10px;
    font-size:18px;
}