@keyframes headShake { 
  0% { transform: translateX(0px); }
  6.5% { transform: translateX(-6px) rotateY(-9deg); }
  18.5% { transform: translateX(5px) rotateY(7deg); }
  31.5% { transform: translateX(-3px) rotateY(-5deg); }
  43.5% { transform: translateX(2px) rotateY(3deg); }
  50% { transform: translateX(0px); }
}
.headShake { animation-timing-function: ease-in-out; animation-name: headShake; }