.mc-wave {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border-radius: inherit;
  pointer-events: none;
  background-color: inherit;
  color: greenyellow;
  box-shadow: 0 0 0 0 var(--mc-button-border-color);
  z-index: -1;
  opacity: 0.4;
}
.mc-wave.is-waving {
  transition: box-shadow 0.4s cubic-bezier(0.08, 0.82, 0.17, 1), opacity 0.5s ease-out;
  box-shadow: 0 0 0 6px var(--mc-button-border-color);
  opacity: 0;
}