style.css

body {
    margin: 0;
    touch-action: none;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;

    background: #333;
    color: #ccc;

    display: flex;
}


* {
    box-sizing: border-box;
}

main {
    width: 100vw;
    height: 100vh;
    display: flex;
    flex-direction: column;
}


nav {
    display: flex;
    position: relative;
    flex-direction: column;
    align-items: center;
    background: #444;
    font-size: max(1.3vw, 12pt);
    overflow: auto;;
}

nav a {
    display: flex;
    align-items: center;
    width: 100%;
    cursor: pointer;
    color: rgb(228, 93, 93);
    text-decoration: none;
    padding: 1em;
}

nav a:hover, nav a.active {
    background: #555555;

}

iframe {
    height: 100%;
}

footer {
    /* position: absolute; */
    bottom: 0;
    padding: 1em;
    width: 100%;
    text-align: center;
}

footer a {
    color: #ccc;
    text-decoration: none;
}

@media only screen and (max-width: 600px) {
    body {
        flex-direction: column;
    }

    nav {
        flex-direction: row;
        align-items: stretch;
    }

    nav a {
        flex: 0 0 8em;
        justify-content: center;
    }
}