animate.css/source/attention_seekers/bounce.css

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% {
    transform: translateY(0);
  }

  40% {
    transform: translateY(-30px);
  }

  60% {
    transform: translateY(-15px);
  }
}

.bounce {
  animation-name: bounce;
}