If that would indeed be all, you’d have all selectors in the document already. So you can decorate with CSS, the pattern would be:
target the topic with a tag
target the post by a member in a primary group
decorate a part of the post
For example:
body.tag-expert-1 {
.topic-post.group-tag-experts-1 {
.cooked {
...
}
}
}
This will only work for primary groups, as they are added to the post as a class selector.
Then you could get for example:
Or set slightly different styles for different Expert groups:
Had just done something similar recently: