.ripple-effect-ctr {
  width: 100px;
  height: 100px;
  animation: growAndFade 1s infinite ease-out;
  background-color: rgb(0, 0, 0);
  position: absolute;
  border-radius: 50%;
  z-index: -1;
}

@keyframes growAndFade {
  0% {
    opacity: 0.3;
    transform: scale(0.5);
  }
  100% {
    opacity: 0;
    transform: scale(1);
  }
}