icinga2/doc/toc.css

#toc {
    top: 0px;
    left: 0px;
    height: 100%;
    position: fixed;
    background: #333;
    box-shadow: inset -5px 0 5px 0px #000;
    width: 250px;
    padding-top: 20px;
    color: #fff;
    overflow:scroll;
}

#toc ul {
    margin: 0;
    padding: 0;
    list-style: none;
}

#toc li {
    padding: 5px 10px;
}

#toc a {
    color: #fff;
    text-decoration: none;
    display: block;
}

#toc .toc-h1 {
    font-size: 1.5em;
}

#toc .toc-h2 {
    font-size: 1.2em;
    padding-left: 10px;
}

#toc .toc-h3 {
    padding-left: 20px;
}

#toc .toc-active {
    background: #336699;
    box-shadow: inset -5px 0px 10px -5px #000;
}