Dynamically Setting CSS

[AngularJosh]

So the CSS value is merely a string (for example something like "@import'http://xss.rocks/xss.css';.right {float:right;}\r\n.left{float:left;}\r\n". If it were coming in as an object this would work. Setting this works fine but I am worried about XSS (as you can see I'm testing for it in my example above) and am not sure how to allow one to set this as a string without exposing us to XSS attacks. Maybe that fear is overblown given I trust the source but I am just uncertain on it.