Reply To: translateX not working in FF with percentage?

[sevensixfive]

Here is a pen where the background doesn’t animate in FF:

http://codepen.io/sevensevenseven/pen/VYxxPB

It is my understanding (possibly wrong) that the values -49% and -897px both move the group of paths named “.ad-clouds” approximately half of the full width of .ad-clouds, before the animation starts over. This gives seamless movement going to the left because it starts over before it runs out of image. The result isn’t the same if it moves to the right.