body {
  background-color: black;
}

.caption {
  color: #dddddd;
  font-size: 1.7em;
}

.link {
  color: #dddddd;
}

.vertical-center {
  min-height: 100%;  /* Fallback for browsers do NOT support vh unit */
  min-height: 100vh; /* These two lines are counted as one :-)       */

  display: flex;
  align-items: center;
}