way to do dynamic css changes with text (either using or not using the main update)

[hanbollar]

          hmmm I still think there might be a need for some stuff in the main update. particularly dynamic CSS updates, which we can't detect changes to via events. 

This is good for now but dynamic CSS changes is a table stakes requirement for V1.

Originally posted by @michaelthatsit in #561 (comment)

[michaelthatsit]

Let's include CSS changes for all UI.

We can already do it with layout (width, position, height, etc). but long term we should target full support.