@keyframes sans {
  0% {top: -150px;}
  25% {top: -90px;}
  96% {top: -90px;}
  100% {top: -150px;}
}

.sans {
  position: relative;
  width: 100px;
  height: 70px;
  left: 85%;
  top: -150px;

  animation-name: sans;
  animation-duration: 20s;
  animation-delay: 1s;
  animation-iteration-count: infinite;
  animation-direction: normal;
  animation-timing-function: linear;
}

.sans-img {
  width: 100%;
  height: 100%;
}