Add some tweaks for the newly introduced video section, fix other issues

Hi Derick,

with some time on the weekend I updated the stylesheets for your new contents and fixed some issues.

One thing I haven't edited is your deployment process with middleman. Unfortunately, there's currently no minification and compressing task for the stylesheets and javascripts. This is normally done by middleman and would have quite an impact on the speed of this site: http://middlemanapp.com/advanced/file-size-optimization/

Keep up the great work with Marionette :)


Bye,
René