.levitation {
  width: 20%;
  transform: rotate(15deg);
  filter: drop-shadow(22px -15px 5px rgba(0, 0, 0, 0.5));
  animation: bouge 8s infinite alternate-reverse;
}

@keyframes bouge {
  /*starting point and angle (same angle as choosen into .levitation)*/
  from {
    transform: translateY(0px) rotate(15deg);
  }
  /* ending point and angle */
  to {
    transform: translateY(50px) rotate(30deg);
  }
}