body {
  margin: 0;
  font-family: 'Open Sans', sans-serif;
  font-size: 18px;
}

.center {
  position: fixed;
  left: 50%;
  top: 50%;
  transform: translateX(-50%) translateY(-50%);
  text-align: center;
  width: min(600px, 96vw);
}