base design system

src/components/Button.tsx

@@ -0,0 +1,9 @@
+import type { ReactNode, ButtonHTMLAttributes } from 'react'
+
+type ButtonVariant = 'primary' | 'secondary' | 'danger' | 'ghost'
+type ButtonProps = ButtonHTMLAttributes<HTMLButtonElement> & { variant?: ButtonVariant; children: ReactNode }
+
+/** Shared action primitive. Visual variants stay in App.css so themes can override them. */
+export function Button({ variant = 'secondary', className = '', children, ...props }: ButtonProps) {
+  return <button className={`button ${variant} ${className}`.trim()} {...props}>{children}</button>
+}