[remedan]

This is off-topic, but I use the Firefox extension Foxy Gestures. When I draw a gesture on the featured website, a pop-up shows the gesture I'm drawing.

I have never seen that before. Is that some JS/CSS trickery? Or a bug in the extension?

[greenmartian]

So I use the same extension and this piqued my interest. On a standard website, FoxyGestures will pop a status box at the bottom, with the gesture you just drew (UDUDLRLR etc). This is done by appending a div at the end of the html body.

It so happens that the website has a CSS style[0] for the last div in the body with no class and no id (search for `body>div:last-child` in the css) - and use it to indicate "admonition-danger" (maybe to show errors?).

[0]: https://mildbyte.xyz/main.css