Had a random idea to implement a <style> tag in Enyo for global runtime CSS manipulation. I’m thinking it might be handy to resize a bunch of elements as a result of window resize, for example. I wrote a quick example in enyo v1 and ported the couple differences for v2.
You can either set the entire CSS via its published css property or set individual blocks via the set(classSpec, styleObject) method.
Edit: Make a quick update to enable removing CSS from a selector by passing a null. See the example below for removing the border from the children of .app.
Here it is live: