html, body {
  height: 100%;
  margin: 0;
  background: #0b0e15; /* dark background */
}

.wrap {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
}

img {
  max-width: 100%;
  max-height: 100%;
  height: auto;
  width: auto;
}