How does iCloud.com hide its source code?

I know you can't hide HTML / Javascript / CSS because it's run on the client side, but how does iCloud.com hide its HTML?

When I view the page source on iCloud.com I just get presented with loads of Javascript, but when I go to inspect element in Chrome I can see the HTML.

I was just curious as to how they did this.

Solution

If you look closer at the page source you'll see this:

#noscript div#container{position:absolute;top:0;left:0;right:0;bottom:0;min-height:500px;}
#noscript div#overlay{position:absolute;top:0;left:0;right:0;bottom:0;min-width:600px;min-height:550px;background:#0B080E;opacity:.84;}
#noscript div#container div.float-center-canvas{z-index:101;position:absolute;background-image:url
....

It seems all the markup is generated in javascript and if javascript isn't enabled they run noscript. Not that anyone would be able to use iCloud without JavaScript in the first place...