Alternative responsive solution

[David Condrey]

Before I found this, I was trying to come up with a pure CSS solution myself and came up with this using the `:active` pseudo selector.  I'm not sure if there may be some benefit to incorporating this into Hint.css to overcome the browser compatibility issues with transitions or for whatever reason but here's a Codepen demo.. http://codepen.io/dcdev/full/JGgpMa/