如何在没有javascript的情况下停止CSS动画

@keyframes example {
  0% {
    background-color: red;
    transform: translateY(0);
  }
  100% {
    background-color: yellow;
    transform: translateY(-20px);
  }
}

.box {
  width: 100px;
  height: 100px;
  background-color: red;
  animation-name: example;
  animation-duration: 2s;
  animation-fill-mode: forwards;
}

.box {
  width: 100px;
  height: 100px;
  background-color: red;
  animation-name: example;
  animation-duration: 2s;
  animation-fill-mode: forwards;
}