@keyframes spulse {
  from {
    transform: scale3d(1, 1, 1);
  }

  50% {
    transform: scale3d(1.25, 1.25, 1.25);
  }

  to {
    transform: scale3d(1, 1, 1);
  }
}

.spulse {
  animation: spulse 2.5s infinite;
  animation-timing-function: ease-in-out;
}