design-system-starter

Design System Starter

Overview

This skill provides comprehensive guidance for building robust, scalable design systems that ensure visual consistency, improve development velocity, and create exceptional user experiences. Whether starting from scratch or evolving an existing system, this framework helps teams design with intention and scale.

When to use this skill:

• Creating a new design system from scratch
• Evolving or refactoring existing design systems
• Establishing design token standards
• Defining component architecture
• Creating design documentation
• Ensuring accessibility compliance (WCAG 2.1)
• Implementing theming and dark mode

Bundled Resources:

• references/component-examples.md - Complete component implementations
• templates/design-tokens-template.json - W3C design token format
• templates/component-template.tsx - React component template
• checklists/design-system-checklist.md - Design system audit checklist

Design System Philosophy

What is a Design System?

A design system is more than a component library—it's a collection of:

1. Design Tokens: Foundational design decisions (colors, spacing, typography)
2. Components: Reusable UI building blocks
3. Patterns: Common UX solutions and compositions
4. Guidelines: Rules, principles, and best practices
5. Documentation: How to use everything effectively

Core Principles

1. Consistency Over Creativity

• Predictable patterns reduce cognitive load
• Users learn once, apply everywhere
• Designers and developers speak the same language

2. Accessible by Default

• WCAG 2.1 Level AA compliance minimum
• Keyboard navigation built-in
• Screen reader support from the start

3. Scalable and Maintainable

• Design tokens enable global changes
• Component composition reduces duplication
• Versioning and deprecation strategies

4. Developer-Friendly

• Clear API contracts
• Comprehensive documentation
• Easy to integrate and customize

Design Tokens

Design tokens are the atomic design decisions that define your system's visual language.

Token Categories

1. Color Tokens

Primitive Colors (Raw values):

{
  "color": {
    "primitive": {
      "blue": {
        "50": "#eff6ff",
        "100": "#dbeafe",
        "200": "#bfdbfe",
        "300": "#93c5fd",
        "400": "#60a5fa",
        "500": "#3b82f6",
        "600": "#2563eb",
        "700": "#1d4ed8",
        "800": "#1e40af",
        "900": "#1e3a8a",
        "950": "#172554"
      }
    }
  }
}

Semantic Colors (Contextual meaning):

{
  "color": {
    "semantic": {
      "brand": {
        "primary": "{color.primitive.blue.600}",
        "primary-hover": "{color.primitive.blue.700}",
        "primary-active": "{color.primitive.blue.800}"
      },
      "text": {
        "primary": "{color.primitive.gray.900}",
        "secondary": "{color.primitive.gray.600}",
        "tertiary": "{color.primitive.gray.500}",
        "disabled": "{color.primitive.gray.400}",
        "inverse": "{color.primitive.white}"
      },
      "background": {
        "primary": "{color.primitive.white}",
        "secondary": "{color.primitive.gray.50}",
        "tertiary": "{color.primitive.gray.100}"
      },
      "feedback": {
        "success": "{color.primitive.green.600}",
        "warning": "{color.primitive.yellow.600}",
        "error": "{color.primitive.red.600}",
        "info": "{color.primitive.blue.600}"
      }
    }
  }
}

Accessibility: Ensure color contrast ratios meet WCAG 2.1 Level AA:

• Normal text: 4.5:1 minimum
• Large text (18pt+ or 14pt+ bold): 3:1 minimum
• UI components and graphics: 3:1 minimum

2. Typography Tokens

{
  "typography": {
    "fontFamily": {
      "sans": "'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif",
      "serif": "'Georgia', 'Times New Roman', serif",
      "mono": "'Fira Code', 'Courier New', 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
      "5xl": "3rem"        // 48px
    },
    "fontWeight": {
      "normal": 400,
      "medium": 500,
      "semibold": 600,
      "bold": 700
    },
    "lineHeight": {
      "tight": 1.25,
      "normal": 1.5,
      "relaxed": 1.75,
      "loose": 2
    },
    "letterSpacing": {
      "tight": "-0.025em",
      "normal": "0",
      "wide": "0.025em"
    }
  }
}

3. Spacing Tokens

Scale: Use a consistent spacing scale (commonly 4px or 8px base)

{
  "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
    "20": "5rem",     // 80px
    "24": "6rem"      // 96px
  }
}

Component-Specific Spacing:

{
  "component": {
    "button": {
      "padding-x": "{spacing.4}",
      "padding-y": "{spacing.2}",
      "gap": "{spacing.2}"
    },
    "card": {
      "padding": "{spacing.6}",
      "gap": "{spacing.4}"
    }
  }
}

4. Border Radius Tokens

{
  "borderRadius": {
    "none": "0",
    "sm": "0.125rem",   // 2px
    "base": "0.25rem",  // 4px
    "md": "0.375rem",   // 6px
    "lg": "0.5rem",     // 8px
    "xl": "0.75rem",    // 12px
    "2xl": "1rem",      // 16px
    "full": "9999px"
  }
}

5. Shadow Tokens

{
  "shadow": {
    "xs": "0 1px 2px 0 rgba(0, 0, 0, 0.05)",
    "sm": "0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px -1px rgba(0, 0, 0, 0.1)",
    "base": "0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1)",
    "md": "0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1)",
    "lg": "0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1)",
    "xl": "0 25px 50px -12px rgba(0, 0, 0, 0.25)"
  }
}

Component Architecture

Atomic Design Methodology

Atoms → Molecules → Organisms → Templates → Pages

Atoms (Primitive Components)

Basic building blocks that can't be broken down further.

Examples:

• Button
• Input
• Label
• Icon
• Badge
• Avatar

Button Component:

interface ButtonProps {
  variant?: 'primary' | 'secondary' | 'outline' | 'ghost';
  size?: 'sm' | 'md' | 'lg';
  disabled?: boolean;
  loading?: boolean;
  icon?: React.ReactNode;
  children: React.ReactNode;
}

See references/component-examples.md for complete Button implementation with variants, sizes, and styling patterns.

Molecules (Simple Compositions)

Groups of atoms that function together.

Examples:

• SearchBar (Input + Button)
• FormField (Label + Input + ErrorMessage)
• Card (Container + Title + Content + Actions)

FormField Molecule:

interface FormFieldProps {
  label: string;
  name: string;
  error?: string;
  hint?: string;
  required?: boolean;
  children: React.ReactNode;
}

See references/component-examples.md for FormField, Card (compound component pattern), Input with variants, Modal, and more composition examples.

Organisms (Complex Compositions)

Complex UI components made of molecules and atoms.

Examples:

• Navigation Bar
• Product Card Grid
• User Profile Section
• Modal Dialog

Templates (Page Layouts)

Page-level structures that define content placement.

Examples:

• Dashboard Layout (Sidebar + Header + Main Content)
• Marketing Page Layout (Hero + Features + Footer)
• Settings Page Layout (Tabs + Content Panels)

Pages (Specific Instances)

Actual pages with real content.

Component API Design

Props Best Practices

1. Predictable Prop Names