Как установить переход в ключе

.box {
 animation-name: bounce;
 animation-duration: 4s; /* or: Xms */
 animation-iteration-count: 10;
 animation-direction: alternate; /* or: normal */
 animation-timing-function: ease-out; /* or: ease, ease-in, ease-in-out, linear, cubic-bezier(x1, y1, x2, y2) */
 animation-fill-mode: forwards; /* or: backwards, both, none */
 animation-delay: 2s; /* or: Xms */
}
Worrisome Whale