Hey Jen :)
I think you misunderstand...I mean I want to be able to write a rule(s) inline (see attached)
Not just select an external file.
So by CodeMirror I mean I'd like the field control that's created to allow the inline css to be syntax highlighted, not just giving us a plain textarea.
Thank you for clarifying.
I have logged a feature quest for this functionality. Please follow the PITS to vote and track its status: