HTML Editor CSS URL problem

I am trying to load an HTML file into the HTML editor. The HTML has a CSS  similar to 

@2375939-face {
font-family: 'FONT-Light';
src: url('https://www.xxx.com/font-Light.eot');
src: url('https://www.xxx.com/font-Light.ttf') format('truetype'), url('https://www.xxx.com/font-Light.woff') format('woff');
font-weight: 400;
font-style: normal;
}

within the <style type="text/css">     </style> section

which directs to some special fonts but the Editor throws an error

Any ideas?  If I use Chrome to go to the URL, the font is automatically downloaded.