:host {
  display: block;
}
.wx-coolui-scroller-item {
  height: 100%;
  position: relative;
  overflow: hidden;
}

.ripple {
  background-color: rgba(0,0,0, 0.2);
  border-radius: 100%;
  height:10px;
  width:10px;
  position: absolute;
  transform: scale(0);
  top: 50%;
}
@keyframes ripple {
  100% {
  transform: scale(80);
  transform: scale(80);
  background-color: transparent;
  }
}