body { 
  background-color: rgba(33,37,41,1);
  color: rgba(25,135,84,1);
  font-size: 2rem;
}
/* cover */
.center {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
}
/* pubkey */
.container {
  text-align: center;
}
.container pre {
  display: inline-block;
  font-size: 1.25rem;
  text-align: left;
}