playground

# Playground Builder A playground is a self-contained HTML file with interactive controls on one side, a live preview on the other, and a prompt output at the bottom with a copy button. The user adjusts controls, explores visually, then copies the generated prompt back into Claude. ## When to use this skill When the user asks for an interactive playground, explorer, or visual tool for a topic — especially when the input space is large, visual, or structural and hard to express as plain text. ## How to use this skill 1. **Identify the playground type** from the user's request 2. **Load the matching template** from `templates/`: - `templates/design-playground.md` — Visual design decisions (components, layouts, spacing, color, typography) - `templates/data-explorer.md` — Data and query building (SQL, APIs, pipelines, regex) - `templates/concept-map.md` — Learning and exploration (concept maps, knowledge gaps, scope mapping) - `templates/document-critique.md` — Document review (suggestions with approve/reject/comment workflow) - `templates/diff-review.md` — Code review (git diffs, commits, PRs with line-by-line commenting) - `templates/code-map.md` — Codebase architecture (component relationships, data flow, layer diagrams) 3. **Follow the template** to build the playground. If the topic doesn't fit any template cleanly, use the one closest and adapt. 4. **Open in browser.** After writing the HTML file, run `open <filename>.html` to launch it in the user's default browser. ## Core requirements (every playground) - **Single HTML file.** Inline all CSS and JS. No external dependencies. - **Live preview.** Updates instantly on every control change. No "Apply" button. - **Prompt output.** Natural language, not a value dump. Only mentions non-default choices. Includes enough context to act on without seeing the playground. Updates live. - **Copy button.** Clipboard copy with brief "Copied!" feedback. - **Sensible defaults + presets.** Looks good on first load. Include 3-5 named presets that snap all controls to a cohesive combination. - **Dark theme.** System font for UI, monospace for code/values. Minimal chrome. ## State management pattern Keep a single state object. Every control writes to it, every render reads from it. ```javascript const state = { /* all configurable values */ }; function updateAll() { renderPreview(); // update the visual updatePrompt(); // rebuild the prompt text } // Every control calls updateAll() on change ``` ## Prompt output pattern ```javascript function updatePrompt() { const parts = []; // Only mention non-default values if (state.borderRadius !== DEFAULTS.borderRadius) { parts.push(`border-radius of ${state.borderRadius}px`); } // Use qualitative language alongside numbers if (state.shadowBlur > 16) parts.push('a pronounced shadow'); else if (state.shadowBlur > 0) parts.push('a subtle shadow'); prompt.textContent = `Update the card to use ${parts.join(', ')}.`; } ``` ## Common mistakes to avoid - Prompt output is just a value dump → write it as a natural instruction - Too many controls at once → group by concern, hide advanced in a collapsible section - Preview doesn't update instantly → every control change must trigger immediate re-render - No defaults or presets → starts empty or broken on load - External dependencies → if CDN is down, playground is dead - Prompt lacks context → include enough that it's actionable without the playground