studio/src/components/mode-toggle.tsx

"use client";

import { useEffect, useState } from "react";
import { Moon, Sun } from "lucide-react";
import { useTheme } from "next-themes";
import { Button } from "@/components/ui/button";

export function ModeToggle() {
  const { resolvedTheme, setTheme } = useTheme();
  const [mounted, setMounted] = useState(false);
  useEffect(() => setMounted(true), []);

  // Avoid a hydration mismatch: render a stable placeholder until mounted.
  const isDark = mounted ? resolvedTheme === "dark" : false;

  return (
    <Button
      variant="ghost"
      size="icon"
      aria-label="Toggle theme"
      title={mounted ? `Switch to ${isDark ? "light" : "dark"} mode` : "Toggle theme"}
      onClick={() => setTheme(isDark ? "light" : "dark")}
    >
      <Sun className="size-4 scale-100 rotate-0 transition-all dark:scale-0 dark:-rotate-90" />
      <Moon className="absolute size-4 scale-0 rotate-90 transition-all dark:scale-100 dark:rotate-0" />
    </Button>
  );
}