Just a note to record a solution in the forum. (RH 8.0.2)
I styled all my topics and then went thru my .css file to clean it up. I added comments and made several element classes (span.note) into independent classes (.note).
When next I needed to style a topic, I opened the Styles and Formatting dialog (Format/Styles...) only to discover that my character styles were now paragraph styles and completely useless to me.
Changing the .css file back to using element classes fixed this.
Hopefully this will save somebody at least a few minutes down the line...