body{  

    padding :0;
    margin :0;
    background-color:black;
    position: absolute;
    top: 0;
    left: 0;
    overflow: auto;
}

/*
#cardclient {
    width: 1000px;
    height: 800px;
    position: absolute;
    top: 50%;
    left: 50%;
    margin: -400px 0 0 -500px;
    overflow: auto;
}
*/