Changing the CSS affects only the preview. I think that @quirkt is talking about the editor here (as others did). And having very basic settings like left/right margin or maximum line width and line spacing would be beneficial in the editor. For anything else, I’d still rather go with an external MD editor.
Interestingly, no one seems ever have to missed better search/replace functionality in DT’s editing environment. That’s something I really need in an editor.
