HTML content showing in edit mode, but stripped when published

Hi all,

I used style elements to create a note container for Guide articles. I checked that it worked locally and then I opened the article HTML editor to copy & paste the paragraph into the article. (I enabled the Display unsafe content.)
In the Guide editor, my style changes work - are rendered. But when I publish the article, my changes are stripped.
These are the style changes I made:
<p style="margin-left:4px;padding-left:2px;border-left:4px solid orange;background-color:#f9f9f9ff" ><b>Important</b><br>Another line.</p> 
Any one got any idea of what I can do so that the content is published?
(New to Zendesk and an HTML beginner.)
Thanks, Patrick