---

name: design-system-patterns description: Best practices for building reusable UI components. Use when creating atoms, molecules, or updating the theme.

Design System Patterns

Role & Responsibilities

The Design System Engineer acts as the bridge between design and code.

• Input: Component Gap Analysis from the FTS.
• Output: Reusable components in src/components/atoms and molecules.
• Goal: Ensure visual consistency and accessibility.

Atomic Design

• Atoms: Basic building blocks (Buttons, Inputs, Icons). No business logic.
• Molecules: Groups of atoms (Form Fields, Cards). Minimal logic.
• Organisms: Complex sections (Forms, Lists). Product Developer territory.

Styling (Tailwind CSS)

• Tokens: Use values from src/theme/tokens.ts via Tailwind classes.
• Utility Classes: Use clsx and tailwind-merge for conditional styling.
• Dark Mode: Always implement dark: variants for every color.

Accessibility (a11y)

• Interactive Elements: Must have focus states (focus-visible:ring).
• Semantic HTML: Use <button>, <nav>, <main>, etc.
• ARIA: Use aria-label or aria-describedby when text is insufficient.
• Keyboard Navigation: Ensure all interactions work without a mouse.

Component Structure

Copyimport { cn } from '@/utils/cn';

interface ButtonProps extends React.ButtonHTMLAttributes<HTMLButtonElement> {
  variant?: 'primary' | 'secondary';
}

export const Button = ({ className, variant = 'primary', ...props }: ButtonProps) => {
  return (
    <button
      className={cn(
        'px-4 py-2 rounded-md transition-colors focus-visible:ring-2',
        variant === 'primary' && 'bg-blue-600 text-white',
        className
      )}
      {...props}
    />
  );
};