html,body{
  margin:0;
  height:100%;
}

.bg {
  background: no-repeat center center fixed;
  background-size: 100% 100%;
  height: 100%;
  width: 100%;
  position: fixed;
}

.bgfade {
  background-color: rgba(20,10,70,0.8);
  background-size: 100% 100%;
  height: 100%;
  width: 100%;
  position: fixed;
}
.semitransparent {
  background-color: rgba(255,255,255,0.7);
}