.six .shape {
  /* animation: six 4s infinite cubic-bezier(0.5,0,0.5,1); */
  animation: six 4s infinite cubic-bezier(0.6,0,0.4,1);
}

@keyframes six {
  0%, 5% {
    transform: translate(-12em);
  }
  45%, 55% {
    transform: translate(12em);
  }
  95%, 100% {
    transform: translate(-12em);
  }
}