html, body {
    width: 100%; height: 100%; padding: 0; margin: 0;
}

#onTop {
    position: absolute;
    left: 0;
    top: 20%;
    width: 100%;
    background-color: rgba(0,0,0,0);
}

#onTop .card {
    background-color: rgba(255,255,255,0.7);
}