animate.css/source/attention_seekers/bounce.css

@keyframes bounce {
  0%, 20%, 53%, 80%, 100% {
    transition-timing-function: cubic-bezier(0.215, 0.610, 0.355, 1.000);
    transform: translate3d(0,0,0);
  }

  40%, 43% {
    transition-timing-function: cubic-bezier(0.755, 0.050, 0.855, 0.060);
    transform: translate3d(0, -30px, 0);
  }

  70% {
    transition-timing-function: cubic-bezier(0.755, 0.050, 0.855, 0.060);
    transform: translate3d(0, -15px, 0);
  }

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

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