img.lazyload {
  opacity: 0;
}
img.lazyloading {
  opacity: 1;
  transition: opacity 300ms;
  background: #c7c7c7 url(/statics/loading.gif) no-repeat center;
  background-size: 3rem;
}
img.lazyloaded {
  z-index: 101;
  background: rgba(0, 0, 0, 0);
}