name: vercel-design-guidelines description: Check web interfaces against Vercel's design guidelines. Use when asked to "review my UI", "check accessibility", "audit design", "review UX", "check my site against best practices", or "apply Vercel design guidelines".

Vercel Design Guidelines

Review web interfaces against Vercel's comprehensive design guidelines and propose fixes.

How It Works

1. Read the user's code (components, CSS, HTML)
2. Check against Vercel design guidelines (interactions, animations, layout, content, forms, performance, design, copywriting)
3. Report violations with specific line references
4. Propose concrete fixes with code examples

Usage

When a user asks to review their UI or check against design guidelines:

1. Fetch the guidelines from both URLs below
2. Read the relevant source files (components, styles, HTML)
3. Analyze the code against each applicable guideline category
4. Report findings grouped by category with severity

Guidelines URLs:

• Structured rules: https://raw.githubusercontent.com/vercel-labs/web-interface-guidelines/refs/heads/main/AGENTS.md (MUST/SHOULD/NEVER directives)
• Full details: https://vercel.com/design/guidelines (rich explanations and examples)

Fetch both for comprehensive coverage — AGENTS.md for structured checklist, full site for context and examples.

Audit Categories

Interactions

• Keyboard accessibility
• Focus management
• Hit targets (minimum 24px, 44px on mobile)
• Loading states
• URL persistence

Animations

• Reduced motion support (prefers-reduced-motion)
• GPU acceleration
• Easing functions
• Interruptibility
• No transition: all

Layout

• Optical adjustment
• Alignment
• Responsive testing
• Safe areas

Content

• Inline help
• Skeleton states
• Empty states
• Typography
• Accessibility

Forms

• Labels (always associated with inputs)
• Validation
• Autocomplete
• Error handling
• Submit behavior

Performance

• Re-renders
• Layout thrashing
• Virtualization
• Preloading

Design

• Shadows
• Borders
• Border radii
• Contrast (APCA standards)
• Color accessibility

Copywriting

• Active voice
• Title case
• Clarity
• Error messaging (show how to fix, not just what's wrong)

Output Format

Present findings as:

## {Category} Issues

### {Severity}: {Guideline Name}
**File:** `path/to/file.tsx:42`
**Issue:** {Description of the violation}
**Guideline:** {Brief guideline reference}
**Fix:**
```{language}
{Proposed code fix}

Severity levels:
- **Critical**: Accessibility violations, broken functionality
- **Warning**: UX issues, performance concerns
- **Suggestion**: Polish, best practices

## Example Review

Interactions Issues

Critical: Keyboard Accessibility

File: components/Modal.tsx:28 Issue: Modal lacks focus trap - keyboard users can tab outside Guideline: Implement focus traps per WAI-ARIA patterns Fix:

// Add focus trap using @radix-ui/react-focus-guards or similar
import { FocusScope } from "@radix-ui/react-focus-scope";

<FocusScope trapped>
  <ModalContent>{children}</ModalContent>
</FocusScope>;

Warning: Loading State Duration

File: components/Button.tsx:15 Issue: No minimum loading duration - causes flicker on fast responses Guideline: Add 150-300ms delay and 300-500ms minimum visibility Fix:

const [isLoading, setIsLoading] = useState(false);
const minimumLoadingTime = 300;

async function handleClick() {
  setIsLoading(true);
  const start = Date.now();
  await action();
  const elapsed = Date.now() - start;
  if (elapsed < minimumLoadingTime) {
    await new Promise((r) => setTimeout(r, minimumLoadingTime - elapsed));
  }
  setIsLoading(false);
}

## Quick Checklist

For rapid reviews, check these high-impact items first:

- [ ] All interactive elements keyboard accessible
- [ ] Visible focus rings on focusable elements
- [ ] Hit targets ≥24px (44px on mobile)
- [ ] Form inputs have associated labels
- [ ] Loading states don't flicker
- [ ] `prefers-reduced-motion` respected
- [ ] No `transition: all`
- [ ] Errors show how to fix, not just what's wrong
- [ ] Color contrast meets APCA standards
- [ ] No zoom disabled

## Present Results to User

After reviewing:

Design Guidelines Audit

Reviewed {N} files against Vercel design guidelines.

Summary

• Critical: {N} issues
• Warning: {N} issues
• Suggestions: {N} items

{Detailed findings by category}

Recommended Priority

1. {First critical fix}
2. {Second critical fix} ...