.toc {
    position: fixed;
    left: 0;
    top: 0;
    bottom: 0;
    padding: 2em 1em;
    overflow-y: auto;
    background: white;
}

.toc .toggle {
    position: fixed;
    padding: 0.4em 0.6em;
    background: #3f3f3f;
    border-radius: 4px;
    box-shadow: 0px 0px 10px 8px rgba(255, 255, 255, 1);
    color: #ddd;
    text-decoration: none;
    cursor: pointer;
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    -khtml-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
    transition: background ease-in-out .15s, color ease-in-out .15s;
}

.toc .toggle:hover {
    background: #313131;
    color: #fff;
}

.toc ul {
    padding-left: 1.25em;
    font-size: 1.2em;
}

.toc > ul {
    margin-top: 3em;
    padding-left: 0;
}

.toc > ul > li > ul > li {
    font-size: 0.75em;
}

.toc > ul > li > ul > li > ul > li {
    font-size: 0.75em;
}

.toc.collapsed {
    background: initial;
}

.toc.collapsed ul {
    display: none;
}