animate.css/source/back_exits/backOutLeft.css

@keyframes backOutLeft {
  0% {
    transform: scale(1);
    opacity: 1;
  }

  20% {
    transform: translateX(0px) scale(0.7);
    opacity: 0.7;
  }

  100% {
    transform: translateX(-2000px) scale(0.7);
    opacity: 0.7;
  }
}

.backOutLeft {
  animation-name: backOutLeft;
}