Dark mode content in React

gistfile1.txt

import React, { useState, useEffect } from "react";

function DarkText() {
  return <h1>hello</>;
}

function LightText() {
    return <h1>world</>;
}

export function useMediaQuery(query) {
  const [matches, setMatches] = useState(false);

  useEffect(() => {
    const media = window.matchMedia(query);
    if (media.matches !== matches) {
      setMatches(media.matches);
    }
  }, [matches, query]);

  return matches;
}

function Theme() {
  let isSiteDark = useMediaQuery("(prefers-color-scheme: dark)");

  return (
    <>
      {isSiteDark && <DarkText />}
      {isSiteDark || <LightText />}
    </>
  );
}