body {
  margin: 0;
  padding: 0;
  background: url('background.png') no-repeat bottom left fixed;
  background-color: black;
  background-size: contain;
}

body::before {
  content: "";
  position: fixed;
  left: 3rem;
  top: 2.5rem;
  background: url('logo.png') no-repeat;
  background-size: contain;
  width: 15rem;
  height: 4rem;
}