.product-item.stock-out {
  position: relative;
}
.product-item.stock-out:after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(255, 255, 255, 0.8);
}
.product-item.stock-out:before {
  content: "商品缺货";
  position: absolute;
  left: 50%;
  top: 50%;
  z-index:999;
  border: 1px solid #363636;
  padding: 6px 25px;
  transform: translate(-50%, -50%);
  border-radius: 3px;
}
.product-item:hover.stock-out {
  transform: scale(1);
}