I would probably create these as CTAs. That will be the easiest way.
You could do it with forms and CSS, but that’s going to be quite a bit more work.
I’d also suggest checking out the service hub and using the NPS survey that’s built right in. It’s not quite a smiley and sad face, but there’s some pretty cool functionality there. If you’d like I’d be happy to walk you through that at your convenience.