Design System Quality

Ensure code meets design system standards for consistency, accessibility, and brand compliance.

Purpose

This skill provides quality gates for UI code reviews, ensuring all frontend work adheres to established design system patterns, accessibility standards, and component conventions.

When to Activate

Use this skill when:

• Reviewing UI/frontend code
• Conducting PR reviews for components
• Checking design system compliance
• After any UI component work

Quality Dimensions

1. Design Token Compliance

Color Usage

CORRECT                           WRONG
var(--bg-primary)                    bg-white
var(--fg-secondary)                  text-gray-500
var(--border-primary)                border-slate-200
bg-bg-primary (Tailwind mapped)      #191919 (hardcoded)

Verification Command:

# Find hardcoded colors (should return empty)
grep -rE "#[0-9A-Fa-f]{3,6}|rgb\(|rgba\(" --include="*.tsx" --include="*.css" | grep -v "var(--"

# Find forbidden Tailwind classes
grep -rE "bg-white|bg-black|text-white|text-black" --include="*.tsx"

Token Categories

2. Component Patterns

Accessible Component Libraries

All interactive elements should use accessible component libraries:

// CORRECT - Using accessible components
import { Button, Input, Select } from 'react-aria-components';
// Or: Radix UI, Headless UI, etc.

// WRONG - Missing accessibility
<button onClick={...}>  // May miss keyboard/screen reader support
<input type="text" />   // May miss ARIA support

Card Pattern

// Standard Card
<div className={cn(
  "bg-bg-secondary",
  "border border-border-secondary",
  "rounded-xl",
  "hover:bg-bg-secondary-hover",
  "hover:border-border-primary",
  "transition-colors duration-150"
)}>

// Wrong patterns
<div className="bg-white rounded-lg shadow">  // Hardcoded colors
<div className="bg-gray-100 border-2">        // Wrong tokens

Button Variants

// Primary (brand color)
className="bg-brand-primary text-white hover:bg-brand-primary-hover"

// Secondary (transparent)
className="bg-transparent border border-border-primary hover:bg-bg-secondary"

// Tertiary (text only)
className="text-fg-secondary hover:text-fg-primary hover:underline"

3. Accessibility Standards

Focus Management

// Focus visible and styled
className="focus:outline-none focus:ring-2 focus:ring-brand focus:ring-offset-2"

// Skip link for keyboard users
<a href="#main-content" className="sr-only focus:not-sr-only">
  Skip to content
</a>

Color Contrast

Minimum Requirements:
- Normal text: 4.5:1 ratio (AA)
- Large text: 3:1 ratio (AA)
- UI components: 3:1 ratio

Best Practice:
- Aim for AAA (7:1 for normal text)
- Test with contrast checkers

Screen Reader Support

// Descriptive labels
<button aria-label="Close dialog">
  <XIcon aria-hidden="true" />
</button>

// Live regions for dynamic content
<div role="status" aria-live="polite">
  {statusMessage}
</div>

4. Typography

Font Hierarchy

/* Display/Headlines */
font-family: var(--font-display);

/* Body text */
font-family: var(--font-body);

/* Code/Monospace */
font-family: var(--font-mono);

Size Scale

• Use the established type scale
• Don't create arbitrary sizes
• Maintain visual hierarchy

5. Animation Standards

Timing Guidelines

/* Micro-interactions: 150ms */
transition-duration: 150ms;

/* UI transitions: 200-300ms */
transition-duration: 200ms;

/* Page transitions: 300-500ms */
transition-duration: 300ms;

Performance Rules

/* GPU-accelerated (prefer these) */
transform: translate(), scale(), rotate();
opacity;
filter;

/* Layout-triggering (avoid animating) */
width, height, padding, margin;
top, left, right, bottom;

/* Never do this */
transition: all 0.3s; /* Animates everything */

Quality Checklist

Use this checklist for every code review:

## Design System Quality Review

### Token Compliance
- [ ] All colors use CSS variables or mapped classes
- [ ] No hardcoded hex/rgb values
- [ ] Borders use semantic tokens
- [ ] Brand colors used appropriately (CTAs only)

### Components
- [ ] Interactive elements use accessible components
- [ ] Card patterns match standard
- [ ] Button variants are correct
- [ ] Focus states visible and styled

### Accessibility
- [ ] Color contrast meets AA minimum
- [ ] Focus management implemented
- [ ] ARIA labels present where needed
- [ ] Keyboard navigation works

### Typography
- [ ] Correct font families used
- [ ] Font sizes from scale
- [ ] Line heights appropriate

### Animation
- [ ] GPU-friendly properties only
- [ ] Timing follows guidelines
- [ ] No jarring transitions

Issue Severity Levels

Critical (Must Fix Before Merge)

• Hardcoded colors bypassing design system
• Missing accessibility on interactive elements
• Broken keyboard navigation
• Insufficient color contrast

Important (Should Fix Before Merge)

• Missing focus states
• Incorrect component variant
• Wrong font family
• Animation timing off

Minor (Track for Future)

• Suboptimal class ordering
• Could use more semantic token
• Animation could be smoother

Automated Checks

Pre-commit Hook Example

# Block hardcoded colors
if grep -rE "#[0-9A-Fa-f]{6}" --include="*.tsx" | grep -v "var(--"; then
  echo "ERROR: Hardcoded colors found. Use design tokens."
  exit 1
fi

CI Quality Gate Example

design-system-check:
  runs-on: ubuntu-latest
  steps:
    - name: Check Token Compliance
      run: |
        ! grep -rE "#[0-9A-Fa-f]{3,6}" --include="*.tsx" | grep -v "var(--"

    - name: Check Accessibility
      run: npx axe-core --include "src/**/*.tsx"

Quick Reference Card

DESIGN SYSTEM QUALITY QUICK CHECK
────────────────────────────────────────────────────────────
Colors:     Use CSS variables or mapped classes
Borders:    border-border-secondary (containers)
Brand:      Brand color for CTAs/active ONLY
Components: Use accessible component libraries
Focus:      Visible ring on all interactive elements
Contrast:   Minimum 4.5:1 for text (AA)
────────────────────────────────────────────────────────────
NEVER: Hardcoded colors, missing focus states
ALWAYS: Design tokens, accessible components

Related Skills

• frontend-design
• verification-before-completion
• brand-guidelines

Version: 1.0.0