Design System Patterns Agent Skill

Design System Patterns

Master design system architecture to create consistent, maintainable, and scalable UI foundations across web and mobile applications.

When to Use This Skill

• Creating design tokens for colors, typography, spacing, and shadows
• Implementing light/dark theme switching with CSS custom properties
• Building multi-brand theming systems
• Architecting component libraries with consistent APIs
• Establishing design-to-code workflows with Figma tokens
• Creating semantic token hierarchies (primitive, semantic, component)
• Setting up design system documentation and guidelines

Core Capabilities

1. Design Tokens

• Primitive tokens (raw values: colors, sizes, fonts)
• Semantic tokens (contextual meaning: text-primary, surface-elevated)
• Component tokens (specific usage: button-bg, card-border)
• Token naming conventions and organization
• Multi-platform token generation (CSS, iOS, Android)

2. Theming Infrastructure

• CSS custom properties architecture
• Theme context providers in React
• Dynamic theme switching
• System preference detection (prefers-color-scheme)
• Persistent theme storage
• Reduced motion and high contrast modes

3. Component Architecture

• Compound component patterns
• Polymorphic components (as prop)
• Variant and size systems
• Slot-based composition
• Headless UI patterns
• Style props and responsive variants

4. Token Pipeline

• Figma to code synchronization
• Style Dictionary configuration
• Token transformation and formatting
• CI/CD integration for token updates

Quick Start

// Design tokens with CSS custom properties
const tokens = {
  colors: {
    // Primitive tokens
    gray: {
      50: "#fafafa",
      100: "#f5f5f5",
      900: "#171717",
    },
    blue: {
      500: "#3b82f6",
      600: "#2563eb",
    },
  },
  // Semantic tokens (reference primitives)
  semantic: {
    light: {
      "text-primary": "var(--color-gray-900)",
      "text-secondary": "var(--color-gray-600)",
      "surface-default": "var(--color-white)",
      "surface-elevated": "var(--color-gray-50)",
      "border-default": "var(--color-gray-200)",
      "interactive-primary": "var(--color-blue-500)",
    },
    dark: {
      "text-primary": "var(--color-gray-50)",
      "text-secondary": "var(--color-gray-400)",
      "surface-default": "var(--color-gray-900)",
      "surface-elevated": "var(--color-gray-800)",
      "border-default": "var(--color-gray-700)",
      "interactive-primary": "var(--color-blue-400)",
    },
  },
};

Detailed patterns and worked examples

Detailed pattern documentation lives in references/details.md. Read that file when the navigation tier above is insufficient.

Best Practices

• Name Tokens by Purpose: Use semantic names (text-primary) not visual descriptions (dark-gray)
• Maintain Token Hierarchy: Primitives > Semantic > Component tokens
• Document Token Usage: Include usage guidelines with token definitions
• Version Tokens: Treat token changes as API changes with semver
• Test Theme Combinations: Verify all themes work with all components
• Automate Token Pipeline: CI/CD for Figma-to-code synchronization
• Provide Migration Paths: Deprecate tokens gradually with clear alternatives

Common Issues

• Token Sprawl: Too many tokens without clear hierarchy
• Inconsistent Naming: Mixed conventions (camelCase vs kebab-case)
• Missing Dark Mode: Tokens that don't adapt to theme changes
• Hardcoded Values: Using raw values instead of tokens
• Circular References: Tokens referencing each other in loops
• Platform Gaps: Tokens missing for some platforms (web but not mobile)