snapdesign-rednote（SnapDesign 红笔记）

RedNote Card Generator

Overview

Use rednote-card-generator to turn any text content into a beautifully styled Xiaohongshu (小红书) carousel post. The output is a single, self-contained HTML string that renders multiple vertical cards (each 450×600 px) stacked vertically with a 20 px gap.

The skill calls the OpenRouter API (model: google/gemini-2.5-flash with fallback to google/gemini-2.5-flash-lite) and streams the HTML response back.

Inputs to collect

Output

Returns a JSON object:

{
  "html": "<!DOCTYPE html>...",
  "cardCount": 5
}

• html: Complete self-contained HTML document. Render this inside an iframe or a sandboxed div.
• cardCount: Estimated number of cards generated.

Actions

Generate cards

{
  "action": "generate",
  "content": "今天分享三个提升专注力的方法...",
  "colorScheme": "warm-brown",
  "openrouterApiKey": "sk-or-..."
}

Color scheme options

Card layout specification

The generated HTML follows these rules so downstream renderers can reliably parse it:

• Outer container: div with display:flex; flex-direction:column; gap:20px
• Each card: div with width:450px; height:600px; position:relative; overflow:hidden
• Card backgrounds: warm paper tones — #FDF8F3, #F5EFE6, #FFFBF5, #F0EBE3 — varied per card
• Top accent strip: div with height:8px; width:100% in a warm accent color
• Typography:

- Card title / section number: 30–38 px, font-weight:700, Playfair Display or Space Grotesk - Body text: 15–17 px, line-height:1.75, Noto Sans SC or Inter - Labels / captions: 12–13 px, muted color

• Text colors: coffee-brown tones #3E2723, #664A42, #5D4037
• Accent shapes: left-border bars (6 px wide), bullet circles (10×10 px), number badges (32×32 px, border-radius 16 px)
• NO emojis in generated content
• Fonts imported via @import inside <style> — never via <link> tags

Card types

The AI selects the best card type for each section of the content:

System prompt used

When calling the LLM, the following system instruction is used:

You are an expert graphic designer who generates production-ready HTML layouts with embedded CSS. Your output is a complete, self-contained HTML document that can be rendered directly in a browser. Output ONLY valid HTML. No markdown, no code fences, no explanation. Include a <style> tag with all CSS. Do NOT use Noto Sans SC. Do NOT set margin or padding on html or body tags. Do NOT use global CSS resets.

User prompt template

The user message sent to the LLM is constructed as follows:

This is a Xiaohongshu (小红书) carousel post. Generate MULTIPLE vertical cards (each 450×600px) stacked vertically with 20px gap between them.

CONTENT FIDELITY — INCLUDE EVERYTHING:
- Cover ALL of the user's text. Do NOT omit, summarize, or skip any sentence.
- Distribute content logically across cards: one topic or section per card.
- Generate as many cards as needed to fit all content (typically 3–10 cards).

Content to include:
"<USER_CONTENT>"

<COLOR_INSTRUCTION>

Return ONLY valid HTML with embedded CSS. No markdown, no code fences, no explanation.

Where <COLOR_INSTRUCTION> is:

• If colorScheme is auto: Analyze the content and choose bold, contextually appropriate colors and modern typography.
• Otherwise: Color Palette — foundation colors are: "<primary>" (primary) and "<secondary>" (secondary). Use them as the dominant palette with tints and shades for depth. Do NOT apply them flatly.

API call details

POST https://openrouter.ai/api/v1/chat/completions
Authorization: Bearer <openrouterApiKey>
Content-Type: application/json

{
  "model": "google/gemini-2.5-flash",
  "messages": [
    { "role": "system", "content": "<SYSTEM_PROMPT>" },
    { "role": "user",   "content": "<USER_PROMPT>" }
  ],
  "stream": true,
  "temperature": 0.4
}

Fallback model order: google/gemini-2.5-flash → google/gemini-2.5-flash-lite

Post-processing steps

After receiving the full streamed HTML, apply these cleanup steps in order:

1. Strip leading/trailing markdown fences ( `html … ` ) if present.
2. Fix broken <img> tags — collapse internal whitespace/newlines to a single space.
3. If the output does not contain <html or <!DOCTYPE, wrap it:

   <!DOCTYPE html><html lang="zh-CN"><head><meta charset="UTF-8"><title>RedNote</title></head><body>…</body></html>

1. Count the number of card div elements to populate cardCount in the response.

Ideas to try

• Paste a WeChat article and get a ready-to-publish 小红书 carousel.
• Summarize a product review into a 5-card visual post.
• Turn meeting notes into a step-by-step visual guide.
• Convert a recipe into numbered-step cards with a title cover.