html, body {
    margin: 0;
    width: 100%;
    height: 100%;
    background: black;
    font-family: -apple-system,BlinkMacSystemFont,"Segoe UI Variable","Segoe UI",system-ui,ui-sans-serif,Helvetica,Arial,sans-serif,"Apple Color Emoji","Segoe UI Emoji";
    overflow: hidden;
}

header {
    position: absolute;
    z-index: 10;
    left: 0;
    top: 0;
    padding: 10px;
    background: rgba(0, 0, 0, 0.50);
    color: #eee;
}

header ul {
    display: inline;
}

header li {
    display: inline;
    margin-right: 20px;
}

a {
    text-decoration: none;
    color: #eee;
}

h1 {
    display: inline;
    font-size: large;
}

@media screen and (max-width: 600px) {
    h1 {
        display: block;
    }

    header ul {
        display: inherit;
    }

    header li {
        display: inherit;
        padding: 5px;
    }

    header {
        width: 100%;
    }
}

iframe {
    width: 100%;
    height: 100%;
}

#overlay {
    z-index: 999;
    position: absolute;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, .75);
    color: white;
    /*display: grid;*/
    display: none;
    place-items: center;
}

#overlay-content li {
    padding: 10px;
}