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

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

#container {
    position: absolute;

    width: 100%;
    height: 100%;

    -webkit-user-select: none; /* Chrome/Safari */
    -moz-user-select: none; /* Firefox */
    -ms-user-select: none; /* IE10+ */
}

#block {
    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: default;

    text-shadow: 1px 3px 9px rgba(0, 0, 0, 0.4),
    3px 6px 8px rgba(0, 0, 0, 0.1),
    -3px 6px 8px rgba(0, 0, 0, 0.1);

}


#heading {
    font-size: xx-large;
}