* {
    box-sizing: border-box;
}

body {
    margin: 0;
    /* Hide scroll bar. */
    overflow: hidden;
}

#debugBox {
    position: fixed;
    width: 800px;
    height: 800px;
    left: 10px;
    top: 10px;
    color: cadetblue;
    font-size: 24pt;
    background: rgba(255, 111, 111, 0.5);
    z-index: 1;
}

#content {
    display: flex;
    flex-direction: column;
}

.page {
    height: 600px;
    border: 10px solid goldenrod;
}