nutui/src/packages/styles/animation/fade.scss

@keyframes nutFadeIn {
  from {
    opacity: 0;
  }

  to {
    opacity: 1;
  }
}

@keyframes nutFadeOut {
  from {
    opacity: 1;
  }

  to {
    opacity: 0;
  }
}
@include make-animation(nutFade);