Comment 2 for bug 752406

We discussed this on IRC. Apparently there is some disagreement about this across LP devs right now. For our squad, we decided on this resolution (from Danilo): we will add our own CSS file and establish a practice for that (bin/combine_css has a simple names=[] variable where we can manually list it for now). That gives us the ability to see what is going on more easily for things that are specific to our code, which is one of my main concerns; while letting us use CSS classes, which many regard as cleaner for all use cases (or at least more use cases that we are using them for now).