.appear[data-src], .appear[data-bkg], .appear [data-src], .appear [data-bkg] {
  opacity: 0;
  -webkit-transition: opacity 1s ease-in;
     -moz-transition: opacity 1s ease-in;
          transition: opacity 1s ease-in;
}
.appeared[data-src], .appeared[data-bkg], .appeared [data-src], .appeared [data-bkg] {
  opacity: 1;
}