// fade 渐变
.fade {
  animation: 0.5s fade;
  &-enter,
  &-leave-to {
    opacity: 0;
  }
  &-enter-active,
  &-leave-active {
    transition: all 0.3s ease;
  }
}
@keyframes fade {
  0% {
    opacity: 0;
  }
  100% {
    opacity: 1;
  }
}