Glad to see you got it working in the end on Chrome. Unfortunately you won’t be able to get it to work in Shotcut because of the old version of the webkit browser engine it uses, which does not support transform-style: preserve-3d; and this is needed to show the 3D aspect of the animation.
I came up against this restriction when I first was developing my WebVfx framework and was hoping Dan would at some stage update to a later version of QTs webkit engine, but this required too much effort on his part.
However, I think I’ve found a way to get the animations (not 3D) to work without having to put them through the converter (i.e. using the CSS as-is). I’ll do the first testing of this tonight.