body {

}

#game, #pass {
    display: none;
    width: 100vw;
    height: 100vh;
}

#gameWindow {
    position: fixed;
    top: 50%;
    left: 50%;
    margin-top: -530px;
    margin-left: -420px;
}

#code {
    border: 1px solid gray;
    border-radius: 25px; /* CSS3 */
    padding: 5px 20px 5px 20px;
    text-align: center;
    position: fixed;
    top: 50%;
    left: 50%;
    width: 200px;
    height: 40px;
    margin-top: -30px;
    margin-left: -100px;
    font-size: 20pt;
}