HTML Playground Builder

Build a self-contained interactive HTML explorer with controls, live preview, and a copyable natural-language prompt.

Workflow

1. Infer the audience, decisions, and required states. Existing design systems and explicit requirements override these defaults.
2. Read exactly one closest template and adapt it:
   • templates/design-playground.md
   • templates/data-explorer.md
   • templates/concept-map.md
   • templates/document-critique.md
   • templates/diff-review.md
   • templates/code-map.md
3. Write one HTML file with inline CSS and JavaScript and no external runtime dependencies.
4. Open it in a desktop browser, interact with every control and preset, and verify live preview, prompt output, copy feedback, empty/error states, and keyboard usability. Fix rendered defects before completion.

Opinionated Defaults

Use these when product context does not indicate otherwise:

• controls beside a live preview, with prompt output below;
• a desktop-browser layout; do not implement or inspect responsive/mobile behavior unless requested;
• a polished light theme, system UI font, monospace code/values, minimal chrome;
• sensible non-empty initial state and 3–5 cohesive named presets;
• one state object, one update path, and immediate preview/prompt refresh;
• controls grouped by concern, with advanced controls collapsed;
• prompt text that explains the desired outcome in natural language and mentions only non-default choices.

Invariants

• No Apply button: relevant changes render immediately.
• The prompt is actionable without seeing the playground and is not a raw state dump.
• Copy has visible transient feedback and a usable fallback when the Clipboard API fails.
• Standardize copy microcopy as Copy prompt, then Copied; on failure show Copy failed — select the prompt below.
• Presets update controls, preview, and prompt consistently.
• Do not add controls that do not affect either the preview or the generated prompt.

Completion requires the self-contained file and rendered, interactive inspection evidence. Finish with ### ✨ Playground ready, the linked artifact, and a compact artifact/controls/desktop-browser/copy-fallback table. Keep generated prompts free of decorative icons unless the requested content needs them.