animate.css/source/attention_seekers/bounce.css

@keyframes bounce {
  from,
  20%,
  53%,
  to {
    animation-timing-function: cubic-bezier(0.215, 0.61, 0.355, 1);
    transform: translate3d(0, 0, 0);
  }

  40%,
  43% {
    animation-timing-function: cubic-bezier(0.755, 0.05, 0.855, 0.06);
    transform: translate3d(0, -30px, 0) scaleY(1.1);
  }

  70% {
    animation-timing-function: cubic-bezier(0.755, 0.05, 0.855, 0.06);
    transform: translate3d(0, -15px, 0) scaleY(1.05);
  }

  80% {
    transition-timing-function: cubic-bezier(0.215, 0.61, 0.355, 1);
    transform: translate3d(0, 0, 0) scaleY(0.95);
  }

  90% {
    transform: translate3d(0, -4px, 0) scaleY(1.02);
  }
}

.bounce {
  animation-name: bounce;
  transform-origin: center bottom;
}