What is happening here and why is it special? The site itself does show, but does not tell (which in itself is somewhat refreshing).
The fade affects scroll bars, which is quite unpleasant (and arguably catastrophic if you have two-dimensional scrolling). The traditional background-image technique avoided this by sitting inside the scroll area. I don’t think you can achieve that with mask, without an additional element. But I think it might be worth that extra element.
This is extremely laggy on my computer. It may not be a top-end gaming supercomputer but it's no slouch either.
hey all, just released a plugin to scratch an itch. i'd been lazily adding linear gradients on the edges of scrollviews and animating them with JS based on scroll position. turns out you can do a lot better with pure CSS now by leveraging masking + the new CSS scroll animations API.
works in pretty much all browers excepting firefox which doesn't have CSS scroll animations yet, but the nightly version does, so it should be generally available soon.
demo site: https://pete.design/tw-fade
github: https://github.com/petekp/tw-fade
npmjs: https://www.npmjs.com/package/tw-fade
if you use it i'd love to hear how it goes and if you have any feedback.
I also love the pure CSS parallax effect of the "tw-fade" title shadow using multiple spans with different styles that fade in and out based on scroll position. Very clever!
FYI scrolling this page is slow as balls on my computer. Firefox on Ubuntu.
I don't know if this page is a demonstration of your plugin, I'm guessing yes but I can't see any masking going on, it seems to scroll just like a normal page but much more laggy.
EDIT: Oh I see in your comment now, it doesn't work in Firefox. My mistake.
Neat! I'd much rather just copy-paste the CSS from the site though, would never install something like this as a package.