var i = 100000;
    var x = document.documentElement.style;
    while(i--){
        x.borderBottom = "1px solid red"
        x.paddingTop="10px"
    }
 
 

 
    var i = 100000;
    var x = document.documentElement;
    while(i--){
        x.cssText= "border-bottom:1px solid red;padding-top:10px"
    }