Vibe Design MD Skill

When: User provides a URL not in the catalog How: Fetch the site, extract design tokens from CSS and visual inspection Accuracy: Good — based on computed styles and visual analysis Time: ~2 minutes

Triggers:

design-md: https://linear.app
design-md: https://resend.com
extract design tokens from https://raycast.com

Step 0 — Parse the request

Determine mode:

Input contains "http" or "https" → Mode B (URL generation)
Input contains a known site name → Mode A (catalog fetch)
Input is ambiguous → check CATALOG.md first, ask if not found

If ambiguous — ask once, concisely:

"Is this [site name] in the catalog (instant) or a URL I should visit and extract?"

Step 1A — Catalog fetch (Mode A)

Read references/CATALOG.md to find the exact slug and fetch URL.

# Fetch from awesome-design-md
curl -fsSL "https://raw.githubusercontent.com/VoltAgent/awesome-design-md/main/design-md/[SLUG]/DESIGN.md" \
  -o DESIGN.md

# Verify download succeeded
if [ -f DESIGN.md ] && [ -s DESIGN.md ]; then
  echo "✅ DESIGN.md downloaded — $(wc -l < DESIGN.md) lines"
  head -20 DESIGN.md
else
  echo "❌ Download failed — falling back to Mode B"
fi

If download succeeds → jump to Step 3. If download fails → fall back to Mode B automatically, tell user.

Step 1B — URL fetch and CSS extraction (Mode B)

Fetch the target site:

# Fetch the page HTML
curl -fsSL "[URL]" -o /tmp/design_target.html 2>/dev/null

# Check if fetch succeeded
wc -c /tmp/design_target.html

Extract what you need from the HTML:

Read /tmp/design_target.html and extract:

1. Font references — <link> tags with Google Fonts or font CDN URLs, @font-face declarations
2. CSS custom properties — any :root { --variable: value } declarations
3. Inline styles and classes — colour values, font sizes, spacing patterns
4. Meta information — <title>, og:description, brand name

Inspect visually (from HTML structure and class names):

• What's the dominant colour? (look for background, button, link colours)
• What font families appear in font links?
• What's the general density? (sparse whitespace vs data-dense)
• What's the layout approach? (centered column, full-width, asymmetric?)
• Dark or light mode primary?

If the site requires JavaScript to render (SPA):

"This site is JavaScript-rendered — I can see the HTML shell but not computed styles. I'll generate DESIGN.md based on visible static content and inferred patterns. For higher accuracy, share a screenshot or the site's public style guide URL." Proceed with what's available. Flag inferred values explicitly.

Step 2 — Generate the DESIGN.md

Read references/DESIGN_MD_FORMAT.md for the exact 9-section structure.

Fill each section from extracted data. Be precise — exact values, not descriptions.

Section 1 — Visual Theme & Atmosphere 2-3 sentences: what does this design feel like? What's the mood, density, philosophy? Example: "Linear uses extreme restraint — near-monochrome surfaces, tight typography, and generous whitespace to create a sense of precision and focus. Every element earns its place. Nothing is decorative."

Section 2 — Color Palette & Roles Every colour with: semantic name, exact hex (and oklch if extractable), functional role.

| Token | Hex | OKLCH | Role |
|-------|-----|-------|------|
| --color-bg | #FFFFFF | oklch(100% 0 0) | Page background |
| --color-text | #0F0F0F | oklch(6% 0 0) | Primary text |
| --color-brand | #5E6AD2 | oklch(50% 0.12 265) | Linear purple — CTAs, links, active states |
| --color-surface | #F7F8F9 | oklch(97% 0.005 240) | Card and sidebar backgrounds |
| --color-border | #E5E7EB | oklch(91% 0.006 240) | Dividers, input borders |

Minimum 6 colours. Include the brand accent even if subtle.

Section 3 — Typography Rules Font families (exact names as they appear in CSS/font links). Full hierarchy table:

| Role | Font | Size | Weight | Line height | Tracking |
|------|------|------|--------|------------|---------|
| Display | [font] | [px/rem] | [number] | [value] | [em] |
| H1 | [font] | [px] | [number] | [value] | [em] |
| H2 | [font] | [px] | [number] | [value] | [em] |
| Body | [font] | [px] | [number] | [value] | [em] |
| Caption | [font] | [px] | [number] | [value] | [em] |
| Mono | [font] | [px] | [number] | [value] | [em] |

Section 4 — Component Styling Buttons, cards, inputs, navigation — with exact values for all states.

### Button (Primary)
- Background: [colour token]
- Text: [colour token]
- Border radius: [px]
- Padding: [px × px]
- Font: [weight, size]
- Hover: background [value], transition [duration ease]
- Active: background [value], scale [value]
- Disabled: opacity [value]
- Focus: outline [colour] [width] offset [value]

Section 5 — Layout Principles Spacing scale (e.g. 4px base, multiples), max-widths, grid, whitespace philosophy.

Section 6 — Depth & Elevation Shadow system with exact box-shadow values for each elevation level.

Level 0 — flat: no shadow
Level 1 — card: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.04)
Level 2 — dropdown: 0 4px 16px rgba(0,0,0,0.12), 0 1px 4px rgba(0,0,0,0.06)
Level 3 — modal: 0 20px 60px rgba(0,0,0,0.16), 0 4px 16px rgba(0,0,0,0.08)

Section 7 — Do's and Don'ts 5-8 specific guardrails for this design language. Example for Linear:

✅ DO: Use weight contrast (300 vs 600) for hierarchy, not size alone
✅ DO: Keep interactive elements subtle — hover should feel discovered, not announced
❌ DON'T: Use colour to convey information (colourblind-safe by design)
❌ DON'T: Add decorative elements — if it doesn't help users, remove it
❌ DON'T: Use more than 2 font weights in any single view

Section 8 — Responsive Behaviour Key breakpoints, how navigation collapses, touch target sizes, what changes on mobile.

Section 9 — Agent Prompt Guide 3 ready-to-use prompts for common UI tasks in this style.

"Build a dashboard sidebar using the Linear DESIGN.md.
 Navigation items: text-only, no icons, active state uses --color-brand background at 8% opacity."

"Create a data table using Linear tokens.
 Headers: --color-text-secondary, 12px, weight 500, uppercase, tracking 0.04em.
 Rows: 1px --color-border bottom, hover --color-surface background."

"Design an empty state using Linear's minimalist approach.
 Short headline, one-line description, single CTA. No illustrations."

Step 3 — Save and validate

# Save to project root
# (already there from curl in Mode A, or write from generation in Mode B)

# Validate it has content
LINES=$(wc -l < DESIGN.md)
SECTIONS=$(grep -c "^## " DESIGN.md)

echo "DESIGN.md: $LINES lines, $SECTIONS sections"

if [ $SECTIONS -lt 7 ]; then
  echo "⚠️ Missing sections — expected 9, found $SECTIONS"
fi

Step 4 — Tell the user

✅ DESIGN.md ready — [Site name]
   [Mode A: "Downloaded from awesome-design-md catalog" /
    Mode B: "Generated from [URL]"]

Design language:
  [One sentence from Section 1]

Key tokens:
  Brand: [colour name + hex]
  Type: [display font] + [body font]
  Surface: [bg colour]

How to use:
  vibe-design reads DESIGN.md automatically.
  Trigger a design pass: design: [what to style]

[If Mode B — inferred values:]
  ⚠️ [N] values were inferred (marked with * in DESIGN.md).
  Verify against the live site before production use.

Step 5 — Offer to update DESIGN_SYSTEM.md

If vibe/DESIGN_SYSTEM.md exists:

"DESIGN.md is ready. Should I also update vibe/DESIGN_SYSTEM.md to use these tokens as the project's design system? This would make all future design passes use [site name]'s visual language by default."

Wait for answer. If yes — update DESIGN_SYSTEM.md with the key tokens. If no — leave as is. DESIGN.md will still be read by vibe-design.

Absolute rules

Never fabricate token values. If a colour can't be extracted, write [EXTRACT FROM SITE] as the value. Inferred values are marked with * and flagged in the Step 4 summary.

DESIGN.md always goes in the project root. Not in vibe/, not in src/. Root only. vibe-design checks ./DESIGN.md — nowhere else.

Mode B accuracy is honest. JS-rendered sites will have incomplete token extraction. Always flag what was inferred vs extracted. Never present an inferred value as definitive.

One DESIGN.md per project at a time. If DESIGN.md already exists, show a diff of what would change:

"DESIGN.md already exists ([current site name]). Replace with [new site]? Or save as DESIGN_[site].md for reference?" Wait for answer.