htmlplayground

name: HtmlPlayground description: "Generate single-file HTML demos comparing techniques side-by-side. USE WHEN preview css, compare css, css demo, show options, visual comparison, html playground, render demo." version: 0.1.0

HtmlPlayground

Generate a self-contained HTML file that renders techniques as side-by-side cards with realistic mock data. Open in browser for visual comparison before committing to production.

When to use

Before adding CSS to a project (snippets, themes, component styles), render the candidates visually so the user can compare and choose.

Instructions

1. Identify the CSS techniques to compare. Sources: conversation context, research findings, user description, or files in the working directory. Each technique becomes one card.

2. For each technique, determine:

   • A short title and source attribution (URL if available)
   • The CSS rules that define it
   • What realistic mock content looks like (tasks, cards, lists, forms — match the user's actual domain)

3. Generate a single HTML file at /tmp/css-preview-{topic}.html with this structure:

   • Dark theme by default using CSS variables (adapts if user prefers light)
   • prefers-color-scheme media query with light mode fallback
   • A grid of cards, one per technique, each self-contained
   • Each card has: title, source link, the rendered demo with realistic data
   • A final card showing all techniques combined (if they layer without conflict)
   • No external dependencies — all CSS inline, all fonts system

4. Open the file in the default browser.

5. Ask the user which techniques to adopt. Options: individual techniques by name, "all", or "none".

6. For adopted techniques, write the CSS to the appropriate location (snippet file, component stylesheet, or new file — based on context).

Card design

Each card is a self-contained demo. Use these conventions:

• Card background slightly darker than page background
• Subtle border, rounded corners (12px)
• Title in the card header with source attribution as small text below
• Demo content uses the same CSS variable names as the target platform (Obsidian vars for vault snippets, standard custom properties for web projects)
• Mock data should feel real — use the user's actual project names, task descriptions, and entity types when known from conversation context

Constraints

• Maximum 6 cards per preview (4 techniques + 1 combined is ideal)
• No JavaScript unless the comparison requires interactivity (hover states, toggles)
• File goes to /tmp/ — never write preview HTML into the project directory
• Source attribution is mandatory when the technique has a known origin