Looks nice but the film-strip cannot be scrolled in Firefox 81.0.2 (desktop, Windows 10, 64bit).
Scroll works for me on Firefox 81.0.1 (64-bit) (desktop/osx)
Works for me on Firefox (desktop, Linux). You've got to use the horizontal scroll though. If your mouse doesn't have a horizontal scroll wheel, try scrolling while holding down shift.
Shift + scroll wheel is working for me, thanks!
I had tried dragging the strip (click + drag) instead which didn't work.
Is there a variant that shows just 1 thumbnail and gif of thumbnails when mouse is hovered?