@keyframes spinner {
  to {transform: rotate(360deg);}
}

.b-lazy {
  -webkit-transition: opacity 500ms ease-in-out;
           -moz-transition: opacity 500ms ease-in-out;
             -o-transition: opacity 500ms ease-in-out;
                transition: opacity 500ms ease-in-out;
                 max-width: 100%;
                   opacity: 0;
}

.b-lazy.b-loaded {
  opacity: 1;
}
.b-lazy:before { /* only applies to background images */
  content: '';
  box-sizing: border-box;
  position: absolute;
  top: 50%;
  left: 50%;
  width: 40px;
  height: 40px;
  margin-top: -20px;
  margin-left: -20px;
  border-radius: 50%;
  border: 2px solid #ccc;
  border-top-color: #1B1B1B;
  animation: spinner .6s linear infinite;
}

.b-lazy.b-loaded:before {
  display: none;
}