I don't see CSS style anywhere. I looked in both Event and Action, nothing there.
There is no Appearence header. For buttons, there is an Appearance Header and one options says Set CSS Style. There is no header for text boxes.
I mean the text boxes where the text is set. Not one where the user inputs text. As in, the text box where it's already set.
You'd think Underlining would be put into Style options along with Bold and Italic.