You can open up your terrain in codepen with nothing but CSS/HTML, and it renders fine. It's just not interactive / draggable anymore.

So the JS is only being used, essentially, as a nice UI for configuring your terrain and the camera angle from which it's viewed.

This is still an incredible feat.

I guess it'd be more accurate to call it a "Generator for CSS-Only Terrain", as the generator itself is not CSS-only.

Not to mention of all of those pesky HTML tags and images, clearly not CSS-only, what a fraud.

Yep. Can confirm this does not work with JS disabled. I'm disappointed by the misleading title.