shadcn/app/components/mode-toggle.tsx

"use client"

import * as React from "react"
import { useTheme } from "next-themes"

import { Button } from "@/registry/default/ui/button"

export function ModeToggle() {
  const { setTheme, resolvedTheme } = useTheme()

  const toggleTheme = React.useCallback(() => {
    setTheme(resolvedTheme === "dark" ? "light" : "dark")
  }, [resolvedTheme, setTheme])

  return (
    <Button
      variant="outline"
      size="icon"
      className="size-8"
      onClick={toggleTheme}
      title="Toggle theme"
      aria-label="Toggle theme"
    >
      <svg
        xmlns="http://www.w3.org/2000/svg"
        width="24"
        height="24"
        viewBox="0 0 24 24"
        fill="none"
        stroke="currentColor"
        strokeWidth="2"
        strokeLinecap="round"
        strokeLinejoin="round"
        className="size-4.5"
      >
        <path stroke="none" d="M0 0h24v24H0z" fill="none" />
        <path d="M12 12m-9 0a9 9 0 1 0 18 0a9 9 0 1 0 -18 0" />
        <path d="M12 3l0 18" />
        <path d="M12 9l4.65 -4.65" />
        <path d="M12 14.3l7.37 -7.37" />
        <path d="M12 19.6l8.85 -8.85" />
      </svg>
      <span className="sr-only">Toggle theme</span>
    </Button>
  )
}