.comment__list-show{

  @mixin com{
    position: absolute;
    top: 0; left: 0;
    background-color: white;
    height: 60px;
    width: 100%;
  }

  &>div:nth-of-type(1) {

    z-index: 3;
    animation: commentSlideShow 12s linear 0s infinite;

    @include com;
  }

  &>div:nth-of-type(2) {
    z-index: 2;
    animation: commentSlideShow 12s linear 4s infinite;

      @include com;
  }

  &>div:nth-of-type(3) {
     z-index: 1;
    animation: commentSlideShow 12s linear 8s infinite;

      @include com;
  }

  @keyframes commentSlideShow {
     25% { opacity: 1;}
     33.33% { opacity: 0;}
     91.66% { opacity: 0;}
     100% { opacity: 1;}
  }
}