html {
  height: 100%;
}

body {
  margin: 5%;
  height: 80%;
}

.parent {
  position: relative;
  width: 100%;
  height: 100%;
}

.parent img {
  position: absolute;
  top: 50%;
  left: 50%;
  margin-right: -50%;
  transform: translate(-50%, -50%);
  width: 50vw;
  height: 38vw;
}