Lovely to see the Material Design language now has a thorough piece considering motion in the browser.
Very interesting point I’ve never considered before with regards to responsive:
“Larger animations on mobile devices are 300-400ms long. Smaller animations can be as short as 150-200ms”
This makes sense; compare an iPad Pro (2732px) against an iPhone 5c (1136px) – that’s more than double the distance on a landscape axis. You wouldn’t expect an element to take the same time to travel those distances, would you?