Beautifully designed, accessible components you own and customize.
Core Pattern: CVA (Class Variance Authority)
Declarative, type-safe variant definitions:
import { cva, type VariantProps } from 'class-variance-authority'
const buttonVariants = cva( // Base classes (always applied) 'inline-flex items-center justify-center rounded-md font-medium transition-colors', { variants: { variant: { default: 'bg-primary text-primary-foreground hover:bg-primary/90', destructive: 'bg-destructive text-destructive-foreground', outline: 'border border-input bg-background hover:bg-accent', ghost: 'hover:bg-accent hover:text-accent-foreground', }, size: { default: 'h-10 px-4 py-2', sm: 'h-9 px-3', lg: 'h-11 px-8', icon: 'h-10 w-10', }, }, compoundVariants: [ { variant: 'outline', size: 'lg', className: 'border-2' }, ], defaultVariants: { variant: 'default', size: 'default', }, } )
// Type-safe props interface ButtonProps extends React.ButtonHTMLAttributes, VariantProps {}
## Core Pattern: cn() Utility
Combines `clsx` + `tailwind-merge` for conflict resolution:
```tsx
import { clsx, type ClassValue } from 'clsx'
import { twMerge } from 'tailwind-merge'
export function cn(...inputs: ClassValue[]) {
return twMerge(clsx(inputs))
}
// Usage - later classes win
cn('px-4 py-2', 'px-6') // => 'py-2 px-6'
cn('text-red-500', condition && 'text-blue-500')
OKLCH Theming (2026 Standard)
Modern perceptually uniform color space:
:root {
--background: oklch(1 0 0);
--foreground: oklch(0.145 0 0);
--primary: oklch(0.205 0 0);
--primary-foreground: oklch(0.985 0 0);
--destructive: oklch(0.577 0.245 27.325);
--border: oklch(0.922 0 0);
--ring: oklch(0.708 0 0);
--radius: 0.625rem;
}
.dark {
--background: oklch(0.145 0 0);
--foreground: oklch(0.985 0 0);
--primary: oklch(0.985 0 0);
--destructive: oklch(0.396 0.141 25.723);
}
Why OKLCH?
- Perceptually uniform (equal steps look equal)
- Better dark mode contrast
- Wide gamut support
- Format:
oklch(lightness chroma hue)
Component Extension Strategy
Wrap, don't modify source:
import { Button as ShadcnButton } from '@/components/ui/button'
// Extend with new variants
const Button = React.forwardRef<
React.ElementRef<typeof ShadcnButton>,
React.ComponentPropsWithoutRef<typeof ShadcnButton> & {
loading?: boolean
}
>(({ loading, children, disabled, ...props }, ref) => (
<ShadcnButton ref={ref} disabled={disabled || loading} {...props}>
{loading && <Spinner className="mr-2" />}
{children}
</ShadcnButton>
))
Quick Reference
# Add components
npx shadcn@latest add button
npx shadcn@latest add dialog
# Initialize in project
npx shadcn@latest init
Key Decisions
| Decision | Recommendation |
|---|---|
| Color format | OKLCH for perceptually uniform theming |
| Class merging | Always use cn() for Tailwind conflicts |
| Extending components | Wrap, don't modify source files |
| Variants | Use CVA for type-safe multi-axis variants |
Related Skills
radix-primitives- Underlying accessibility primitivesdesign-system-starter- Design system patternsbiome-linting- Code quality for components
References
- CVA Variant System - CVA patterns
- OKLCH Theming - Modern color space
- cn() Utility - Class merging
- Component Extension - Extending components
- Dark Mode - next-themes integration