Trying to style Comments Plus form

I really tried to avoid posting this question because I think it shoud be easy to solve. But it's beaten me. I'm just trying to add some vertical space in the elements of the Comments Plus form.

Specifically under the text: "Click on a tab to select hoe you'd like to leave your comment", and especially to move the blue comment submission button down 10px ( see screengrab).

I'm in the comments-specific.css file, but it doesn't seem to like margin commands.

thanks