html, body {
    margin:0;
    padding:0;
    height: 100%;
}
#background {
    background : #000000 url("background.jpg") no-repeat bottom left;
    background-size: 100% 100%;
    min-height:100%;
}
.center {
    text-align: center;
    vertical-align: middle;
    padding-top: 4cm;
  }