html, body {
  margin: 0;
  width: 100%;
  min-height: 100%;
}

body {
  min-height: 100vh;
  background-color: #000;
  background-image: url("cosmic-background.png");
  background-size: contain;
  background-position: center center;
  background-repeat: no-repeat;
  background-attachment: fixed;
}