I can’t look at the source right now (on my tablet), but I’m guessing it’s just some static HTML/CSS with a bit of JavaScript? You could throw that up at any web host (free or paid) in a matter of minutes.
15 years ago it might have been Lycos or Geocities, today it might be GitHub Pages or Netlify. I’m not sure about 15 years from now, but if web browsers as we know them are still around then, there will almost certainly be a service that can host a bit of HTML/CSS/JS around too.
15 years ago it might have been Lycos or Geocities, today it might be GitHub Pages or Netlify. I’m not sure about 15 years from now, but if web browsers as we know them are still around then, there will almost certainly be a service that can host a bit of HTML/CSS/JS around too.