html,
body {
    background-color: #333;
    color: #ccc;
    margin: 0;
    height: 100%;
}

main {
    height: 100%;
    overflow-y: auto;
    font-size: 2rem;
}

div.current {
    background-color: #000;
}

span.current {
    background-color: #fc3;
    color: #000;
}

audio {
    width: 100%;
    position: sticky;
    bottom: 0;
}