JSFiddle - React, Tailwind, and code Playground
by gionaf
HTML
<div id="yourdiv">
</div>
<span id="logger"></span>
CSS
#yourdiv {
background:yellow;
width:200px;
height:200px;
}
#yourdiv.backgrounded {
background:url(http://i444.photobucket.com/albums/qq165/junah42/Snark/idiocracy10qg3.png) top left no-repeat;
}
JavaScript
var logger = $('#logger');
var yourdiv = $('#yourdiv');
$(window).on('load resize',function(){
var w=window,
d=document,
e=d.documentElement,
g=d.getElementsByTagName('body')[0];
var docWidth = w.innerWidth||e.clientWidth||g.clientWidth;
if(docWidth>600){
yourdiv.addClass('backgrounded');
}
logger.html('Width: '+docWidth);
});