.is-loading {
  animation: blink 0.4s infinite;
  background-color: lightgray;
  background: lightgray;
  color: gray;
  cursor: wait;
}

@keyframes blink {
  0% {
    opacity: 1;
  }

  50% {
    opacity: 0.75;
  }

  100% {
    opacity: 1;
  }
}