Whether CSS nesting works for inline styles isn't actually defined in the specs, as far as I can find.

So I was under the assumption that I could do:

<ul style="
   & a {
    font-weight:bold;
    &:link {color:green}
    &:is(:hover, :active) {color:red} 
  }">
  <li><a href="#">Home</a></li>
  <li><a href="#">Blog</a></li>
  <li><a href="#">About</a></li>
 </ul>

And found out that no, it doesn't work.

I'm hoping that this behaviour can be defined at the very least, and allowed if at all possible.

By allowing nesting to work with inline styles, it creates a very useful method to scope CSS styles.