server side rendering with multiple pages.

Let's imagine I'm building an app with `rcss` and want to do server side rendering.

I have two simple pages `/` and `/about` that have their own elements and styles.

Because `rcss` has a global registry the call to `.getStylesString()` would return the styles for both sites when I only want to insert the styles for a single page into that page.

How do you imagine this approach scaling ? A component cannot have a notion of "what pages am I on". The top level page component somehow needs to say "for all" styles in my render call, insert them.

Not really sure how one would do that.

The issue describes server-side rendering for `/` and `/about`, with `getStylesString()` reading a global registry; start by tracing that rendering path and registry behavior. Done would require an agreed approach for isolating styles per page and validating separate page renders, but the issue does not name files or tests.

Written by the indexing model from the issue text.