CSS selector limit for IE (below 10)

[hanwentao]

There is a limit of at most 4096 selectors in a single CSS file in IE (below 10). And application.css & course.css both hit the limit. Please refer to http://railslove.com/blog/2013/03/08/overcoming-ies-4096-selector-limit-using-the-css-splitter-gem for more information.

[singingwolfboy]

We've fixed this in https://github.com/edx/edx-platform/pull/1365. Thanks for the report!