2sxc icon picker not showing the font icons

Does the 2sxc icon picker work when the CSS file is hosted off site like on a CDN? I'm trying to set up the icon picker field with a CSS file that's hosted on MaxCDN and I can't seem to figure out how to get it to work. I've been able to configure the fuel type to work when the CSS files located within the portals but for some reason when the CSS file it's outside the portal I can't seem to get it to work. Is there something special that I need to do? Screenshot of configuration

This is a security issue in all browsers. So you can use the external css for runtime, but in the edit dialog you must provide a css file which comes from the same server - sorry. Otherwise the dialog cannot "scan" the css to provide the previews / search.