The bottom half of the page doesn't even show in FF on MacOS for me... just white...

Text selection also doesn't seem to work... is it all Canvas maybe?

Also FF on MacOS, and same issue. Seems like a hang

Firefox on Android, too.

Doesn't load with mobile browser bur if you change to 'desktop site' option it loads... but is very jittery and loads slow, a few visual bugs aswell.

and Firefox on Linux.

Seconded (Firefox on Linux), it worked fine with the toggles but once it came to the map-based examples it stopped. Never saw a map scroll, and continuing down the page started to blank out the (assumed to be) maps, so I closed the tab.

Very nice-looking page, but perhaps a smidgen over-engineered for what it wanted to show? :)

Perhaps it's worth filing a bug report if this works on other browsers but not FF.

Reported it here: https://github.com/webcompat/web-bugs/issues/134506

Example of form over function.

If the site doesn't even load, does it matter what function you use for the toggle in the settings page?

It's nice, but it's not nice enough to warrant going beyond transition: all and timing cubic-bezier in css. Maybe if browsers ever add native support without having to add extra overhead.

For me the final few animations do some funky things... flickering, phasing out of bounds...

Can reproduce. Almost like it's intentional...

Same issue. Android FF just won't handle this "basic modern website". Probably 5+MB of js being loaded in.