html,
body {
  height: 100%;
}

body {
  margin: 0;
  display: grid;
  place-items: center;
  background: #f9f8f4;
}

img {
  display: block;
  max-width: 100vw;
  max-height: 100vh;
  max-height: 100dvh;
  width: auto;
  height: auto;
}