html {
     background: black;
     width: 100%;
     height:100%;
     min-height:100%;
}
body {
    margin: 0px;
    padding: 0px;
    width: 100%;
    height: 100%;
    overflow: hidden;
}

.game-background, #main-background {
    content: "";
    position: fixed;
    width: 200%;
    height: 200%;
    top: -50%;
    left: -50%;
    z-index: -1;
    background: url(img/backgrounds/tile.png) 0 0 repeat;
    -webkit-transform: rotate(-13deg);
    transform: rotate(-13deg);
}

.game-background:before {
    position: relative;
    overflow: hidden;
    -webkit-transform: rotate(13deg);
    transform: rotate(13deg);
}