Build a Design System

Based on the Design Graph methodology by Brent Jackson and mathematical typography principles.

When This Activates

• "Create a design system"
• "Set up design tokens"
• "Build a component library"
• "Create a theme"
• "Establish a type scale"
• "Structure my styles"

The Design Graph

A constraint-based system with 4 interconnected nodes:

SCALES ──────► COMPONENTS
   │                │
   │                │
   ▼                ▼
THEMES ◄────── VARIANTS

1. Scales

Raw design values mapped to specific properties.

const scales = {
  colors: {
    primary: '#0066cc',
    secondary: '#666',
    background: '#fff',
    text: '#1a1a1a',
    muted: '#f5f5f5',
  },

  // Powers of 2 spacing (base 4 or 8)
  space: [0, 4, 8, 16, 32, 64, 128],

  // Mathematical type scale (1.25 ratio)
  fontSizes: [12, 14, 16, 20, 24, 32, 48],

  // Limited font weights
  fontWeights: {
    normal: 400,
    medium: 500,
    bold: 700,
  },

  // Consistent radii
  radii: [0, 2, 4, 8, 16, 9999],
}

Rules:

• Use powers of 2 for spacing: 4, 8, 16, 32, 64
• Limit to 6-7 values per scale (matches heading levels)
• Name semantically where possible (primary, muted)

2. Components

UI elements constrained by scales.

const Button = {
  // Base styles (always applied)
  padding: scales.space[2], // 8px
  fontSize: scales.fontSizes[2], // 16px
  fontWeight: scales.fontWeights.medium,
  borderRadius: scales.radii[2], // 4px

  // Only use values from scales - never magic numbers
}

Rules:

• Components ONLY reference scale values
• No magic numbers (no padding: 13px)
• Base styles define the default state

3. Variants

Partial styles for contextual changes.

const variants = {
  buttons: {
    primary: {
      bg: 'primary',
      color: 'white',
    },
    secondary: {
      bg: 'transparent',
      color: 'primary',
      border: '1px solid',
      borderColor: 'primary',
    },
    ghost: {
      bg: 'transparent',
      color: 'text',
    },
  },

  text: {
    heading: {
      fontWeight: 'bold',
      lineHeight: 1.25,
    },
    body: {
      fontWeight: 'normal',
      lineHeight: 1.5,
    },
    caption: {
      fontSize: 0, // scales.fontSizes[0]
      color: 'muted',
    },
  },
}

Rules:

• Variants are additive (applied on top of base)
• Name by purpose, not appearance (primary, not blue)
• Keep variants minimal (3-5 per component)

4. Themes

Collections of scales that define visual language.

const lightTheme = {
  colors: {
    text: '#1a1a1a',
    background: '#ffffff',
    primary: '#0066cc',
    muted: '#f5f5f5',
  },
}

const darkTheme = {
  colors: {
    text: '#f5f5f5',
    background: '#1a1a1a',
    primary: '#66b3ff',
    muted: '#333333',
  },
}

Rules:

• Themes swap scales, not components
• Same keys, different values
• Components automatically adapt

Mathematical Typography

Use powers of 2 for a mathematically coherent system:

BASE: 16px (2⁴) = 1rem

TYPE SCALE (1.25 ratio):
- xs:   12px  (0.75rem)
- sm:   14px  (0.875rem)
- base: 16px  (1rem)
- lg:   20px  (1.25rem)
- xl:   24px  (1.5rem)
- 2xl:  32px  (2rem)
- 3xl:  48px  (3rem)

SPACING (powers of 2):
- 4px  (0.25rem)
- 8px  (0.5rem)
- 16px (1rem)
- 32px (2rem)
- 64px (4rem)

LINE HEIGHT:
- Headings: 1.25
- Body: 1.5
- Tight: 1.125

Why powers of 2:

• Digital displays are binary
• Common screen sizes divisible by 16
• Halving/doubling always yields integers
• Creates subtle mathematical relationships

Output Format

When building a design system, output:

DESIGN SYSTEM SPEC

SCALES:
  colors: [list with hex values]
  space: [array in px]
  fontSizes: [array in px]
  fontWeights: [object]
  radii: [array in px]

COMPONENTS:
  [ComponentName]:
    base: [styles referencing scales]
    variants: [list]

THEMES:
  light: [scale overrides]
  dark: [scale overrides]

IMPLEMENTATION:
  [Code for theme provider, tokens, or CSS variables]

Quick Start Template

// theme.ts
export const theme = {
  colors: {
    text: '#1a1a1a',
    background: '#ffffff',
    primary: '#0066cc',
    secondary: '#666666',
    muted: '#f5f5f5',
    border: '#e5e5e5',
  },
  space: [0, 4, 8, 16, 32, 64],
  fontSizes: [12, 14, 16, 20, 24, 32],
  fontWeights: { normal: 400, medium: 500, bold: 700 },
  lineHeights: { tight: 1.25, normal: 1.5 },
  radii: [0, 4, 8, 16, 9999],
}

Anti-Patterns

References

• Design Graph - Brent Jackson
• Mathematical Web Typography - Brent Jackson
• Two Steps Forward - CSS methodology evolution