div.single {
  -webkit-background-size: 50% 100%;
  -moz-background-size: 50% 100%;
  -ms-background-size: 50% 100%;
  -o-background-size: 50% 100%;
  background-size: 50% 100%; }

div.double {
  -webkit-background-size: 50% 100%, 75% 100%;
  -moz-background-size: 50% 100%, 75% 100%;
  -ms-background-size: 50% 100%, 75% 100%;
  -o-background-size: 50% 100%, 75% 100%;
  background-size: 50% 100%, 75% 100%; }
