Shadcn

Shadcn UI Developer Guide

This skill provides guidelines, patterns, and best practices for working with shadcn/ui components in this project.

Quick Start

1. Core Patterns: Read references/patterns.md for comprehensive styling, theming, and component patterns.
2. Tailwind Integration: For Tailwind CSS patterns, use the tailwindcss skill.

Core Philosophy

• Ownership: Shadcn is copy-paste, not a dependency - you own the code.
• Customization: Components are meant to be modified for your needs.
• Accessibility: Built on Radix UI primitives for proper accessibility.
• Flexibility: Styled with Tailwind CSS for easy customization.

Critical: Design Token Usage

Always use design system tokens for theme switching compatibility:

Required tokens:

• Backgrounds: bg-background, bg-card, bg-muted, bg-popover
• Text: text-foreground, text-muted-foreground, text-card-foreground
• Borders: border-border, border-input, border-ring
• Actions: bg-primary text-primary-foreground, bg-secondary text-secondary-foreground
• States: bg-destructive text-destructive-foreground, bg-accent text-accent-foreground

Never use explicit colors like bg-white, text-black, border-gray-200 - they break theme switching.

Common Tasks

Adding Components

Use the CLI to add components, then customize as needed:

npx shadcn@latest add button card dialog

Extending Components

Add custom props and variants while preserving accessibility:

export interface ButtonProps
  extends React.ButtonHTMLAttributes<HTMLButtonElement>,
    VariantProps<typeof buttonVariants> {
  loading?: boolean
}

const Button = React.forwardRef<HTMLButtonElement, ButtonProps>(
  ({ className, variant, size, loading, children, ...props }, ref) => {
    return (
      <button
        className={cn(buttonVariants({ variant, size, className }))}
        ref={ref}
        disabled={loading || props.disabled}
        {...props}
      >
        {loading && <Loader2 className="mr-2 h-4 w-4 animate-spin" />}
        {children}
      </button>
    )
  }
)

Compound Components

Always use separate exports, NOT namespaced properties:

// CORRECT
export const CardTech = CardTechRoot;
export const CardTechHeader = CardHeader;
export const CardTechTitle = CardTitle;
export const CardTechContent = CardContent;

// WRONG - Do not use
export const CardTech = Object.assign(CardTechRoot, {
  Header: CardHeader,
  Content: CardContent,
});

Preserving Accessibility

Never remove Radix UI's accessibility attributes:

<Dialog>
  <DialogTrigger asChild>
    <Button>Open Dialog</Button>
  </DialogTrigger>
  <DialogContent>
    <DialogHeader>
      <DialogTitle>Accessible Title</DialogTitle>
      <DialogDescription>
        This description helps screen readers understand the dialog's purpose
      </DialogDescription>
    </DialogHeader>
  </DialogContent>
</Dialog>

Theming

Use CSS variables for all color values in globals.css:

@layer base {
  :root {
    --success: 142 76% 36%;
    --success-foreground: 355 100% 100%;
  }

  .dark {
    --success: 142 76% 46%;
    --success-foreground: 142 76% 10%;
  }
}

Validation Checklist

Before finishing a task involving shadcn/ui:

• Verify all colors use design tokens, not explicit values.
• Ensure accessibility attributes from Radix UI are preserved.
• Test keyboard navigation works correctly.
• Use separate exports for compound components (not namespaced).
• Run type checks (pnpm run typecheck) and tests (pnpm run test).

For comprehensive patterns, component examples, and detailed guidelines, read references/patterns.md.