@keyframes slideIn {
  from {
    top: -100%;
  }
  to {
    top: 0;
  }
}

#message.slideIn {
  animation: slideIn 0.25s forwards;
}

#message {
  display: none;
  position: fixed;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  color: #fff;
  z-index: 1;
}