Single HTML Artifact

Default Stack

Use this stack unless the user asks otherwise:

• One .html file with embedded <style> and <script>.
• Custom CSS with CSS variables for theme, spacing, borders, and status colors.
• Vanilla JavaScript for static pages and simple interactions.
• Alpine.js from CDN when stateful UI would otherwise require repetitive DOM code.
• Optional CDN libraries only when they clearly reduce complexity: Chart.js for charts, Mermaid for diagrams, highlight.js for code, KaTeX for math.

Avoid build tools, package managers, JSX transpilers, large component libraries, and app frameworks unless the artifact is truly a mini-app or the user requests them.

Workflow

1. Clarify the artifact's job: document, comparison, dashboard, prototype, editor, or review aid.
2. Choose the smallest interaction model:
   • Static reading: HTML + custom CSS.
   • Tabs, filters, toggles, forms, copy/export: add Alpine.js.
   • Many reusable components or nested state: consider Preact, but explain the tradeoff.
3. Build the first screen as the usable artifact, not a landing page.
4. Keep the layout readable: clear hierarchy, dense but calm spacing, responsive constraints, and no overlapping text.
5. Add export affordances when the user will make decisions in the artifact: copy as Markdown, JSON, prompt, or diff.
6. Verify by opening in a browser or otherwise checking the generated HTML for syntax, layout, and interaction issues.

CSS Guidance

Prefer custom CSS over a UI framework. Define a small token set:

:root {
  --bg: #f7f7f4;
  --panel: #ffffff;
  --text: #1f2328;
  --muted: #687076;
  --accent: #2563eb;
  --border: #d9dee3;
}

Use framework CSS only when it fits the artifact:

• Pico.css: good for document-like pages with forms, tables, and prose.
• Tailwind CDN: acceptable for quick prototypes mostly maintained by AI, but expect noisy HTML.
• DaisyUI, Flowbite, Bootstrap, Material, shadcn-style systems: usually too heavy for single-file artifacts.

Alpine.js Pattern

Use Alpine.js when the page needs light state:

<script
  defer
  src="https://cdn.jsdelivr.net/npm/alpinejs@3.x.x/dist/cdn.min.js"
></script>

<main x-data="{ tab: 'why' }">
  <button @click="tab = 'why'">Why</button>
  <section x-show="tab === 'why'">...</section>
</main>

Keep state close to the markup it controls. For larger logic, define named functions inside the page script and initialize them with x-data="artifact()".

Quality Bar

Before finishing:

• Confirm the file is self-contained except for intentional CDN links.
• Ensure the core content remains readable if optional scripts fail.
• Check mobile and desktop responsiveness.
• Check buttons, tabs, filters, and export actions.
• Keep the final report concise: file path, what changed, verification, and any known tradeoffs.