body {
  background: #f1f1f1;
  margin: 0;
  padding: 0;
}
img {
  width: 200px;
  display: block;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}
.gif {
  width: 100vw;
  height: 100vh;
  position: relative;
}