@keyframes myAnimation {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

.animated-element {
  animation-name: myAnimation;
  animation-duration: 1s;
  animation-timing-function: ease;
  animation-delay: 0s;
  animation-iteration-count: 1;
  animation-direction: normal;
  animation-fill-mode: forwards;
  animation-play-state: running;
}

/* 简写 */
.animated-element {
  animation: myAnimation 1s ease 0s 1 normal forwards;
}