Setting paragraph right margin? (ePub)

I need to make some paragraphs a little bit indented on both the left and right margins.
Paragraphs are narrower than the main body, for example to emphasize or a citation.
I created a style that moves a paragraph more to the right, but I can’t figure out how to add a large right margin just for selected paragraphs. The ruler doesn’t seem to be of any help.
When compiled to ePub and/or Kindle, it is aligned on the right body margin.

Here is what I would need (left) and what I get (right)

Any clue on how to do this?
Thanks for any light you can shed on my ignorance :smiley:
Steve J

As I understand it, ePub is HTML and HTML has no right margin.