!function(n){var e=n.document,t=e.documentElement,i=750,d=i/50,o="orientationchange"in n?"orientationchange":"resize",a=function(){var n=t.clientWidth||320;n>750&&(n=750),t.style.fontSize=n/d+"px"};e.addEventListener&&(n.addEventListener(o,a,!1),e.addEventListener("DOMContentLoaded",a,!1))}(window);

$fsz:50;
@function rem($value){
    @return  $value/$fsz*1rem;
}
.fsz{
    font-size: rem(100)
}