html {
    overflow-y: auto;
}
body {
    max-width: 600px;
    margin: 40px auto;
    padding: 0 10px;
    font: 14px/1.5 monospace;
    color: white;
    background: #444;
}
h1,
h2,
h3 {
    line-height: 1.2;
}
a:link {
    color: #5bf;
}
a:visited {
    color: #ccf;
}
pre {
    color: #ffffff;
    background: #000000;
    padding: 24px;
    white-space: pre-wrap;
}
summary + * {
    color: #5bf;
}