How can I change the animation speed in a certain period of time?

Question

css

Good day. There is an animation:

.s {animation: ssline 12s; transition-timing-function:  ease-out; }

There are just 2 keyframes in ssline, start height and end height. The problem is this:
How to leave the ease-out animation speed and at the same time insert two short intervals in two places, in which the speed will increase greatly (5 times)? That is, the animation goes as standard with ease-out, and let's say at 6 seconds and at 8 seconds the speed increases sharply for half a second and then returns to normal

Answer 1

https://webref.ru/css/keyframes
Check out this article. Good luck