React component for responsive background

responsive-bg-react.jsx

...

  React.useEffect(() => {
    if (parentRef && parentRef.current) {
      parentRef.current.style.setProperty("--bg-mobile", mobileFileUrl);
      parentRef.current.style.setProperty("--bg-tablet", tabletFileUrl);
      parentRef.current.style.setProperty("--bg-desktop", desktopFileUrl);

      parentRef.current.classList.add("bg-background-set");
    }
  }, [
    desktopFileUrl,
    mobileFileUrl,
    parentRef,
    tabletFileUrl,
  ]);

  return null;
}