html, body { height: 100%; margin: 0; padding: 0; }
body {
  background: #15202b;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
img {
  display: block;
  max-width: 80vw;
  max-height: 80vh;
  width: auto;
  height: auto;
  object-fit: contain;
}