body {
  margin: 0; }

#container {
  width: 100vw;
  height: 100vh;
  overflow: hidden; }

#item {
  -webkit-animation: x 8s linear infinite alternate;
  animation: x 8s linear infinite alternate;
  width: 1px;
  height: 1px; }

img {
  width: 20rem;
  height: 10rem;
  -webkit-animation: y 6s linear infinite alternate;
  animation: y 6s linear infinite alternate; }

@-webkit-keyframes x {
  100% {
    -webkit-transform: translateX(calc(100vw - 20rem));
    transform: translateX(calc(100vw - 20rem)); } }

@keyframes x {
  100% {
    -webkit-transform: translateX(calc(100vw - 20rem));
    transform: translateX(calc(100vw - 20rem)); } }

@-webkit-keyframes y {
  100% {
    -webkit-transform: translateY(calc(100vh - 10rem));
    transform: translateY(calc(100vh - 10rem)); } }

@keyframes y {
  100% {
    -webkit-transform: translateY(calc(100vh - 10rem));
    transform: translateY(calc(100vh - 10rem)); } }