body {
    margin: 0;
    position: absolute;
    font-family: sans-serif;
    width: 100%;
    height: 100%;

    display: flex;
    flex-direction: column;
}

iframe, textarea {
    flex: 1 0 auto;
    width: 100%;
}
body {
    margin: 0;
    position: absolute;
    font-family: sans-serif;
    width: 100%;
    height: 100%;

    display: flex;
    flex-direction: column;
}

iframe, textarea {
    flex: 1 0 auto;
    width: 100%;
}

textarea {
    font-family: monospace;
}

Set monospaced font in textarea
Set monospaced font in textarea
