@keyframes pulse-ring 
{
  0% {
      transform: scale(.5);
      opacity: 1;
  }
  100% {
      transform: scale(1.5);
      opacity: 0;
  }
}

.pulse-ring::before 
{
  content: '';
  margin-inline: 4px 12px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background-color: red;
  animation: pulse-ring 1.5s infinite ease-in-out;
}