Looks great!
As for learning more, you’ve pretty much covered what there is to know! The concept is pretty simple in Scrivener: make styles that have that “raw markup” checkbox enabled and have at it, either with those prefix and suffix fields or by typing in your own stuff in the editor. Section Layouts are worth playing with a bit as well, particularly if you have larger sections of text that should be treated differently.
In fact what we did here was slightly more advanced. In a lot of cases you can just get away with non-markup styles. The thing to know is that when you apply a named style to any text, Scrivener converts that name to a CSS style in the output, even if it isn’t in the compile settings. In that way you can do anything to paragraphs, or spans of text within them, Scrivener itself doesn’t handle with its basic formatting conversion.
Beyond that it’s learning what bits and pieces of HTML and CSS you can whenever you want to do something interesting like this. And of course you’ve got this forum as well. We have a number of people here that know their way around and can figure out ways of doing things you may only initially have a design idea for.
One trick I use is to get a program like Sigil or Calibre so you can look at the .epub itself directly, rather than having to relying on read-only previewers like Kindle Previewer. Not only do they give you a look at what’s really going on under the surface, both have “live editing”, meaning you can play with the numbers or colours in the CSS file and make things look just right, then copy and paste the result back into Scrivener’s CSS pane to make it permanent. Being able to see what you’re doing directly isn’t just a tool for experts, it’s a great way to learn.