.highlight-overlay {
  position: fixed;
  z-index: 9998;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;

  opacity: .6;

  background: @black;
  background: -webkit-radial-gradient(50% 20%, ellipse farthest-corner, rgba(0, 0, 0, 0.6), rgba(0, 0, 0, 1));
  background:         radial-gradient(50% 20%, ellipse farthest-corner, rgba(0, 0, 0, 0.6), rgba(0, 0, 0, 1));

  -webkit-animation: highlight-overlay-fadein 0.5s;
  animation: highlight-overlay-fadein 0.5s;
}

.highlight-target {
  z-index : 9999;
  position : relative;
}

.highlight-overlay-fadein() {
  from {
    opacity: 0;
  }
  to {
    opacity: 0.6;
  }
}

@-webkit-keyframes highlight-overlay-fadein { .highlight-overlay-fadein; }
@keyframes highlight-overlay-fadein { .highlight-overlay-fadein; }