html, body, #container {
    width: 100%;
    height: 100%;
    margin: 0;
    background: #444;
}
body {
    font: 13px/1.4 system-ui, sans-serif;
}
#monitor {
    position: absolute;
    z-index: 2;
}
#main canvas {
    position: absolute;
    z-index: 1;
}
#main {
    position: absolute;
    background-color: black;
}

/* Cog menu, bottom right (built by codef.js from the page's <footer>) */
footer {
    position: absolute;
    text-align: right;
    left: 0;
    right: 0;
    bottom: 0;
    color: white;
}
#cog {
    padding: 4px 8px;
    border: 0;
    background: transparent;
    color: white;
    font-size: 20px;
    line-height: 1;
    cursor: pointer;
}
#modal_wrapper {
    position: relative;
}
#modal {
    display: none;
    z-index: 10;
    position: absolute;
    text-align: center;
    left: 0;
    right: 0;
    bottom: 0;
    color: black;
    background: #fff;
    padding: 1em;
}
#cog:hover + #modal, #cog:focus + #modal, #modal:hover, #modal:focus-within {
    display: block;
}
#modal a, #modal button {
    display: inline-block;
    margin: 2px;
    padding: 4px 10px;
    border: 1px solid #ccc;
    border-radius: 3px;
    background: #fff;
    color: #333;
    font: inherit;
    text-decoration: none;
    cursor: pointer;
}
#modal a:hover, #modal button:hover {
    background: #e6e6e6;
}
#modal a.on {
    border-color: #2e6da4;
    background: #337ab7;
    color: white;
}
#modal a[href$=".zip"]::before {
    content: "\2193\00a0";
}

/* Start screen, when the browser waits for a click before playing sound */
#start {
    position: fixed;
    inset: 0;
    z-index: 20;
    width: 100%;
    border: 0;
    background: rgba(0, 0, 0, 0.6);
    color: white;
    font: bold 24px system-ui, sans-serif;
    letter-spacing: 0.1em;
    cursor: pointer;
}