.item-thumbnail:before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0,0,0,0);
  transition: background .35s;
  border-radius: 8px;
  z-index: 2;
  max-width: 765px;
  margin: 0 auto;
  pointer-events: none;
  padding-left: 10px
}

.item-thumbnail:after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 40px;
  height: 40px;
  margin: -20px 0 0 -20px;
  background: url(这里放图片地址);background-repeat: no-repeat;
  background-size: 100% 100%;
  z-index: 3;
  -webkit-transform: scale(2);
  transform: scale(2);
  transition: opacity .35s,-webkit-transform .35s;
  transition: transform .35s,opacity .35s;
  transition: transform .35s,opacity .35s,-webkit-transform .35s;
  opacity: 0;
  pointer-events: none;
}

.item-thumbnail:hover:before {
  background: rgba(0,0,0,.5)
}

.item-thumbnail:hover:after {
  -webkit-transform: scale(1);
  transform: scale(1);
  opacity: 1
}
/*www.huijuf.com*/