/* fade image in after load */
.lazyload,
.lazyloading {
    opacity: 0;
}
.lazyloaded {
    opacity: 1;
    transition: opacity 300ms;
}

/* fade image in while loading and show a spinner as background image (good for progressive images) */

.lazyload {
    opacity: 0;
}

.lazyloading {
    opacity: 1;
    transition: opacity 300ms;
    background: #f7f7f7 url(loader.gif) no-repeat center;
}