design-system-starter

What this skill does

# Design System Starter

Build robust, scalable design systems that ensure visual consistency and exceptional user experiences.

---

## Quick Start

Just describe what you need:

```
Create a design system for my React app with dark mode support
```

That's it. The skill provides tokens, components, and accessibility guidelines.

---

## Triggers

| Trigger | Example |
|---------|---------|
| Create design system | "Create a design system for my app" |
| Design tokens | "Set up design tokens for colors and spacing" |
| Component architecture | "Design component structure using atomic design" |
| Accessibility | "Ensure WCAG 2.1 compliance for my components" |
| Dark mode | "Implement theming with dark mode support" |

---

## Quick Reference

| Task | Output |
|------|--------|
| Design tokens | Color, typography, spacing, shadows JSON |
| Component structure | Atomic design hierarchy (atoms, molecules, organisms) |
| Theming | CSS variables or ThemeProvider setup |
| Accessibility | WCAG 2.1 AA compliant patterns |
| Documentation | Component docs with props, examples, a11y notes |

---

## 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):
```json
{
  "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):
```json
{
  "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

```json
{
  "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)

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

#### 4. Border Radius Tokens

```json
{
  "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

```json
{
  "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:**
```typescript
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:**
```typescript
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
- Use