Animation Timing Function
default(ease)
ease-in
ease-out
ease-in-out
linear
step-start
step-end
steps(n, jump-start)
steps(n, jump-end)
steps(n, jump-none)
steps(n, jump-both)
steps(n, start)
steps(n, end)
cubic-bezier(p1, p2, p3, p4)
MDN reference