html.style

Machine-readable

For agents

A model already knows the HTML specification. This framework needs no extra vocabulary for the baseline, and a manifest for everything past it.

custom-elements.json

Shipped at dist/custom-elements.json, declared as customElements in package.json, and exported from the npm package.

"customElements": "dist/custom-elements.json",
"exports": {
  "./custom-elements.json": "./dist/custom-elements.json"
}
Copy

llms.txt

This site serves llms.txt — a short index of what to load for a given task.

System prompt you can paste

You are generating HTML for html.style v2026.1.
- Prefer semantic HTML with no classes. Tags are already styled.
- Use layout atoms only when needed: stack, cluster, switcher, center, grid, card-grid.
- Use hs-* elements only to add behaviour the platform lacks. They wrap real elements when possible (hs-dialog → dialog, hs-accordion → details, hs-field → input, hs-sortable → table).
- Theme via CSS custom properties (--p-brand-hue, --color-*). Do not invent a parallel palette.
- Do not add polyfills. Do not target browsers below Chrome 131 / Firefox 133 / Safari 18.
- Read custom-elements.json for attributes, events, slots, parts, and CSS properties.
Copy

Naming that stays predictable

  • Elements: hs-*
  • Events: hs-* (hs-close, hs-tab-change)
  • Primitives: --p-*
  • Semantic color: --color-*