[pmwiki-users] embedded css stylesheets

I'm having difficulty with the (:stylesheet:) tags. I think I understand how it works but I must be missing something in the implementation. The code doesn't appear to be understood except as display text. I updated to 2.1.27 but it doesn't help. I have an example I'm working with in my sandbox:

[pmwiki-users] CSS Popup

I'm having difficulty with the (:stylesheet:) tags. I think I understand how it works but I must be missing something in the implementation. The code doesn't appear to be understod except as display text. I updated to 2.1.27 but it doesn't help. I have an example I'm working with in my sandbox: h