.frost-layer {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  background-color: rgba(0,0,0,.2);
  transition: all .5s cubic-bezier(0.5, -0.5, 0.3, 1.4);
}

.frost {
  -webkit-filter: blur(3px);
  filter: blur(3px);
  transition: all .5s cubic-bezier(0.5, -0.5, 0.3, 1.4);
}