Css transform origine

#cube {
  background-color: red;
  height: 200px;
  width: 200px;
  display: inline-block;
  top: 100px;
  left: 100px;
  position: absolute;
  animation-delay: 10s;
  animation-duration: 10s;
  transform: rotate(20deg);
  transform-origin: -50% -50%;
}