html,
body {

    height: 100%;
}

body {

    background: white;
    margin: 0;
    overflow: hidden;
    user-select: none;
}

#container {

    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
}

#start {

    background: black;
    color: white;
    font-family: consolas;
    border: 2px solid black;
    padding: 20px;
    font-size: 40px;
    cursor: pointer;
}

#okay {

    background: black;
    color: white;
    font-family: consolas;
    border: 2px solid black;
    padding: 20px;
    font-size: 40px;
    cursor: pointer;
    margin-top: 40px;
}

#end {

    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
}

#end div {

    background: 0;
    color: black;
    font-family: consolas;
    border: 2px solid black;
    padding: 20px;
    margin: 0 200px;
    font-size: 40px;
}