@keyframes blink {
  0% { background-color: rgba(0, 0, 255, 1); }
  50% { background-color: rgba(0, 0, 255, 0); }
  100% { background-color: rgba(0, 0, 255, 1); }
  }
.r {
  background: blue;
  color: #000000;
  animation: blink 1s infinite;}