So the class prefix is actually `-*`, not `*`:

> The Class Prefix Selector is currently limited to hyphen-separated prefixes, at least at first. Other separators, like _, might be added as possibilities in the future as we receive request from authors like yourself about what would be needed.

I'm sorry, but how did they think this a good idea? Why treat the hyphen with special qualities over any other non-whitespace separator? The argument around "accidental overselection" seems pretty weak to me. If you're using a character with known special properties like the asterisk in CSS then you should understand you're wielding a more powerful hammer implicitly.