using css classes

I've been following this tutorial: http://www.edgedocks.com/content/2013/12/using-customized-css-animate-compositions

but I'm running into a few issues. The first one is that any elements styled using classes don't appear as such in the edge environment, only when previewing in browser. The other issue is that Edge keeps stripping the css classes that I've added manually to its html file everytime I save the document from edge.

Am I doing something wrong?

Thanks