Themes are a combination of CSS classes, HTML templates and potentially subdynamics.

The `default` theme is automatically applied to the player if not otherwise specified and looks as follows:

<iframe width="100%" height="290px" src="http://jsfiddle.net/betajs/1vt9y816/3/embedded/html,result/" allowfullscreen="allowfullscreen" frameborder="0"></iframe>

The `modern` theme can be manually applied:

<iframe width="100%" height="290px" src="http://jsfiddle.net/betajs/8gznkemj/3/embedded/html,result/" allowfullscreen="allowfullscreen" frameborder="0"></iframe>