.bounce {
  animation: bounce 2s 3;
}

@keyframes bounce {
  0%  { transform: translateY(0); }
  20% { transform: translateY(0); }
  30% { transform: translateY(-10px); }
  40% { transform: translateY(-5px); }
  50% { transform: translateY(5px); }
  60% { transform: translateY(0); }
  80% { transform: translateY(-5px); }
  100% { transform: translateY(0); }
}