button {
  position: relative;
  overflow: hidden;
}

span.ripple {
  position: absolute;
  border-radius: 50%;
  background-color: rgba(6, 58, 168, 0.25);
  opacity: 1;
  transform: scale(0);
  animation: ripple 1s;
}

@keyframes ripple {
  to {
    transform: scale(4);
    opacity: 0;
  }
}