Re: [csswg-drafts] [css-cascade] Additive CSS (#1594)

Hello. I thought of another interesting theoretical use case for additive CSS beyond transitions and animations. If CSS property values could be of types `triple` and `quad`, then one would be able to form metadata graphs and datasets by means of additive CSS.

```css
@namespace deo url('http://purl.org/spar/deo');
@namespace doco url('http://purl.org/spar/doco');
@namespace rdf url('http://www.w3.org/1999/02/22-rdf-syntax-ns#'); 

p
{
    metadata: triple(this(), url(rdf|type), url(doco|Paragraph)) !add;
}

p.introduction
{
    metadata: triple(this(), url(rdf|type), url(deo|Introduction)) !add;
    metadata: triple(this(), url('http://example.org#property'), literal('This is the introduction.', 'en')) !add;
}

p.important
{
    metadata: triple(this(), url('http://example.org#property'), literal('This is important.', 'en')) !add;
}
```

```html
<p class="introduction important">...</p>
```

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Received on Monday, 13 April 2026 08:52:37 UTC