html, body {
    width: 100%;
    height: 100%;
}

body {
    background-color: #ffffff;
    margin: 0;
    overflow: hidden;
    font-family: arial;
}

#blocker {

    z-index: 1;

    position: absolute;

    width: 100%;
    height: 100%;

    background-color: rgba(0,0,0,0.5);

}

#instructions {

    width: 100%;
    height: 100%;

    display: -webkit-box;
    display: -moz-box;
    display: box;

    -webkit-box-orient: horizontal;
    -moz-box-orient: horizontal;
    box-orient: horizontal;

    -webkit-box-pack: center;
    -moz-box-pack: center;
    box-pack: center;

    -webkit-box-align: center;
    -moz-box-align: center;
    box-align: center;

    color: #ffffff;
    text-align: center;

    cursor: pointer;
}