[Stitch4223]

What is happening here and why is it special? The site itself does show, but does not tell (which in itself is somewhat refreshing).

[lelandfe]

This is an effect that is widely used but is generally done with JS.

The effect indicates to users who may not have scroll bars enabled that a box can be scrolled. The fade should be removed when a box can’t be scrolled in that direction.

CSS effects tend (tend) to be faster and conceptually is a better place for effects anyway (e: and works with JS disabled, which is cool)

[Stitch4223]

Ah, thanks! It looks like it only works if there is something partially shown. The fade color being the same as the background will just make it look like background when margins between scrollable objects are too wide. Good to know this exists.