html, body{
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
}
body{
    background:  rgba(0, 0, 0, 0) linear-gradient(rgb(56, 56, 56), rgb(122, 122, 122)) repeat scroll 0% 0%;
}
#canvas{
    top: 0;
    left: 0;
    position: fixed;
}