Frontend Design System

A skill for production-grade UI design. Supports consistent, scalable frontend development through clear design tokens, layout rules, motion guidelines, and accessibility checks.

When to use this skill

• Production-quality UI needed: Generate high-quality UI from prompts

• Consistent design language: Maintain a unified visual language across screens

• Typography/layout/motion guidance: Systematic design system

Instructions

Step 1: Define Design Tokens

// design-tokens.ts

export const tokens = {

  // Colors

  colors: {

    primary: {

      50: '#EFF6FF',

      100: '#DBEAFE',

      500: '#3B82F6',

      600: '#2563EB',

      700: '#1D4ED8',

    },

    secondary: {

      500: '#6366F1',

      600: '#4F46E5',

    },

    accent: '#F59E0B',

    success: '#10B981',

    warning: '#F59E0B',

    error: '#EF4444',

    background: {

      primary: '#FFFFFF',

      secondary: '#F9FAFB',

      tertiary: '#F3F4F6',

    },

    text: {

      primary: '#1F2937',

      secondary: '#6B7280',

      tertiary: '#9CA3AF',

      inverse: '#FFFFFF',

    },

  },

  // Typography

  typography: {

    fontFamily: {

      sans: ['Inter', 'system-ui', 'sans-serif'],

      mono: ['JetBrains Mono', 'monospace'],

    },

    fontSize: {

      xs: '0.75rem',     // 12px

      sm: '0.875rem',    // 14px

      base: '1rem',      // 16px

      lg: '1.125rem',    // 18px

      xl: '1.25rem',     // 20px

      '2xl': '1.5rem',   // 24px

      '3xl': '1.875rem', // 30px

      '4xl': '2.25rem',  // 36px

    },

    fontWeight: {

      normal: 400,

      medium: 500,

      semibold: 600,

      bold: 700,

    },

    lineHeight: {

      tight: 1.25,

      normal: 1.5,

      relaxed: 1.75,

    },

  },

  // Spacing (8px base unit)

  spacing: {

    0: '0',

    1: '0.25rem',  // 4px

    2: '0.5rem',   // 8px

    3: '0.75rem',  // 12px

    4: '1rem',     // 16px

    5: '1.25rem',  // 20px

    6: '1.5rem',   // 24px

    8: '2rem',     // 32px

    10: '2.5rem',  // 40px

    12: '3rem',    // 48px

    16: '4rem',    // 64px

  },

  // Border Radius

  borderRadius: {

    none: '0',

    sm: '0.25rem',  // 4px

    md: '0.375rem', // 6px

    lg: '0.5rem',   // 8px

    xl: '0.75rem',  // 12px

    '2xl': '1rem',  // 16px

    full: '9999px',

  },

  // Shadows

  shadows: {

    sm: '0 1px 2px 0 rgb(0 0 0 / 0.05)',

    md: '0 4px 6px -1px rgb(0 0 0 / 0.1)',

    lg: '0 10px 15px -3px rgb(0 0 0 / 0.1)',

    xl: '0 20px 25px -5px rgb(0 0 0 / 0.1)',

  },

  // Breakpoints

  breakpoints: {

    sm: '640px',

    md: '768px',

    lg: '1024px',

    xl: '1280px',

    '2xl': '1536px',

  },

};

Step 2: Define Layout + UX Goals

page_spec:

  type: "landing" | "dashboard" | "form" | "blog" | "e-commerce"

  hierarchy:

    primary_action: [Main CTA]

    secondary_actions: [Secondary actions]

    information_architecture:

      - section: hero

        priority: 1

      - section: features

        priority: 2

      - section: social_proof

        priority: 3

      - section: cta

        priority: 4

  responsive:

    mobile_first: true

    breakpoints:

      - mobile: "< 640px"

      - tablet: "640px - 1024px"

      - desktop: "> 1024px"

    stack_behavior: "vertical on mobile, horizontal on desktop"

Step 3: Generate UI Output

Component structure by section:

// Hero Section

<section className="hero">

  <div className="container">

    <div className="hero-content">

      <Badge>New Release</Badge>

      <Heading level={1}>

        Main Headline Here

      </Heading>

      <Paragraph size="lg">

        Supporting copy that explains the value proposition

        in 1-2 sentences.

      </Paragraph>

      <div className="cta-group">

        <Button variant="primary" size="lg">

          Primary CTA

        </Button>

        <Button variant="secondary" size="lg">

          Secondary CTA

        </Button>

      </div>

    </div>

    <div className="hero-visual">

      <Image src="hero-image.png" alt="Product screenshot" />

    </div>

  </div>

</section>

Motion/interaction notes:

/* Motion Guidelines */

:root {

  /* Duration */

  --duration-fast: 150ms;

  --duration-normal: 300ms;

  --duration-slow: 500ms;

  /* Easing */

  --ease-in-out: cubic-bezier(0.4, 0, 0.2, 1);

  --ease-out: cubic-bezier(0, 0, 0.2, 1);

  --ease-in: cubic-bezier(0.4, 0, 1, 1);

}

/* Hover States */

.button {

  transition: all var(--duration-fast) var(--ease-in-out);

}

.button:hover {

  transform: translateY(-1px);

  box-shadow: var(--shadow-md);

}

/* Page Transitions */

.page-enter {

  opacity: 0;

  transform: translateY(10px);

}

.page-enter-active {

  opacity: 1;

  transform: translateY(0);

  transition: all var(--duration-normal) var(--ease-out);

}

Step 4: Validate Accessibility

## Accessibility Checklist

### Color Contrast (WCAG 2.1 AA)

- [ ] Text/background: 4.5:1 minimum (normal text)

- [ ] Text/background: 3:1 minimum (large text)

- [ ] UI components: 3:1 minimum

### Keyboard Navigation

- [ ] All interactive elements focusable

- [ ] Focus order logical (left→right, top→bottom)

- [ ] Focus indicator visible

- [ ] Skip links present

### Screen Reader

- [ ] Semantic HTML used

- [ ] Images have alt text

- [ ] Form labels associated

- [ ] ARIA labels where needed

### Text & Readability

- [ ] Minimum 16px body text

- [ ] Line height ≥ 1.5

- [ ] Paragraph width < 80 characters

- [ ] No text in images

Step 5: Handoff

## Design Handoff Package

### Component Breakdown

| Component | Props | Variants |

|-----------|-------|----------|

| Button | size, variant, disabled | primary, secondary, ghost |

| Input | size, error, placeholder | default, error, success |

| Card | padding, shadow | elevated, flat, outlined |

### CSS/Token Summary

- Colors: [link to color palette]

- Typography: [link to type scale]

- Spacing: 8px base unit

- Breakpoints: 640/768/1024/1280px

### Files

- Figma: [link]

- Tokens: design-tokens.ts

- Components: /src/components/

Examples

Example 1: SaaS Landing Page

Prompt:

Design a SaaS landing page with modern typography,

soft gradients, and subtle motion.

Include hero, features, pricing, and CTA.

Expected output:

• Section layout with visual direction

• Typography scale (H1: 48px → Body: 16px)

• Color palette with gradient definitions

• Motion/interaction specifications

• Component list with props

Example 2: Admin Dashboard

Prompt:

Create a clean admin dashboard with data cards,

filters, and tables. Focus on clarity and fast scanning.

Expected output:

• Grid layout (12-column)

• Component breakdown (cards, tables, filters)

• Visual hierarchy documentation

• Responsive behavior specification

Example 3: Mobile-First Form

Prompt:

Design a multi-step form optimized for mobile.

Include progress indicator, validation states,

and success confirmation.

Expected output:

• Step-by-step flow diagram

• Form field specifications

• Error/success state designs

• Touch-friendly sizing (min 44px targets)

Best practices

• Start with content hierarchy: UI follows content priority

• Consistent spacing scale: 8px-based system, no ad-hoc spacing

• Motion with intent: Only animate meaningful transitions

• Test on mobile: Verify layout integrity

• Accessibility first: Consider accessibility at the design stage

Common pitfalls

• Overusing effects and gradients: Keep it simple

• Inconsistent typography scale: Use the defined scale

• Ignoring accessibility: Check color contrast and keyboard navigation

Troubleshooting

Issue: UI feels generic

Cause: No visual direction or tokens defined

Solution: Provide style references and a color palette

Issue: Layout breaks on mobile

Cause: No responsive grid rules defined

Solution: Define breakpoints and stacking behavior

Issue: Inconsistent components

Cause: Tokens not being used

Solution: Reference all values from tokens

Output format

## Design System Report

### Tokens Applied

- **Colors**: [primary, secondary, accent]

- **Typography**: [font-family, scale]

- **Spacing**: [base unit, scale]

- **Shadows**: [levels]

### Section Layout

| Section | Grid | Components |

|---------|------|------------|

| Hero | 2-col | Badge, Heading, CTA |

| Features | 3-col | Card, Icon |

| Pricing | 3-col | PricingCard |

| CTA | 1-col | Button |

### Component List

- [ ] Button (primary, secondary, ghost)

- [ ] Card (elevated, flat)

- [ ] Input (default, error)

- [ ] Badge

- [ ] Icon

### Accessibility Audit

- [x] Contrast ratios pass

- [x] Focus indicators visible

- [x] Semantic HTML

Multi-Agent Workflow

Validation & Retrospectives

• Round 1 (Orchestrator): Visual direction, section completeness

• Round 2 (Analyst): Accessibility, hierarchy review

• Round 3 (Executor): Handoff checklist verification

Agent Roles

Agent

Role

Claude

Token definition, component design

Gemini

Accessibility analysis, reference research

Codex

CSS/component code generation

Metadata

Version

• Current Version: 1.0.0

• Last Updated: 2026-01-21

• Compatible Platforms: Claude, ChatGPT, Gemini, Codex

Related Skills

• ui-component-patterns

• responsive-design

• web-accessibility

• image-generation

Tags

#frontend #design #ui #ux #typography #animation #design-tokens #accessibility