html, body {
  background-color: black;
  height: 100%;
  overflow-y: hidden;
}
body {
  position: fixed;
  width: 100%;
}

.Aligner {
  display: flex;
  align-items: center;
  min-height: 12em;
  justify-content: center;
}

#mars {
  width: 5%;
  border-radius: 50%;
}

.full-height {
  height: 97vh;
}
.centered {
  text-align: center;
}