/* To pretify things */
ul {
    list-style: none;
    padding: 0;
    margin: 0;
}
ul li {
    margin: .25em 0;
}

a {
    width: 100%;
    display: block;
    background: rgba(0, 0, 0, 0.2);
    color: #222;
    padding: 1em 1.5em;
    border-radius: 0.15em;
    -webkit-transition: background .3s ease;
    transition: background .3s ease;
    text-decoration: none;
    position: relative;
}
a:hover {
    background: rgba(0, 0, 0, 0.3);
}

li.has-child:not(.is-active):not(.has-active-child) > a:after {
    content: "";
    display: block;
    position: absolute;
    height: .5em;
    width: .5em;
    border-top: 2px solid #333;
    border-right: 2px solid #333;
    -webkit-transform: rotate(135deg);
    transform: rotate(135deg);
    top: 50%;
    right: 1.5em;
    margin-top: -0.5em;
}

li.has-active-child > a {
    color: #fff;
}
li.has-active-child > a:after {
    content: "";
    display: block;
    position: absolute;
    height: .5em;
    width: .5em;
    border-top: 2px solid white;
    border-right: 2px solid white;
    -webkit-transform: rotate(-45deg);
    transform: rotate(-45deg);
    top: 50%;
    right: 1.5em;
    margin-top: -0.15em;
}

li li.is-active > a {
    color: #fff;
}
li li.is-active > a:after {
    content: "";
    display: block;
    position: absolute;
    height: .8em;
    width: .34em;
    border-top: 2px solid white;
    border-left: 2px solid white;
    -webkit-transform: rotate(-135deg);
    transform: rotate(-135deg);
    top: 50%;
    right: 1.5em;
    margin-top: -0.6em;
}

.has-active-child > a {
    color: #fff;
    background-color: rgba(0, 128, 0, 0.5);
}
.has-active-child > a:hover {
    background-color: rgba(0, 128, 0, 0.7);
}

.is-active > a {
    color: #fff;
    background-color: green;
    cursor: default;
}

/* serious fluff */
h1 {
    font-size: 2.5em;
    margin-bottom: .9em;
}

* {
    box-sizing: border-box;
    font-weight: 300;
}

code {
    border: 1px solid #ccc;
    background-color: #f4f4f4;
    border-radius: 5px;
    padding: 2px;
    font-size: 0.9em;
}

p {
    line-height: 1.6;
    margin-bottom: 3em;
}

body {
    width: 90%;
    max-width: 728px;
    margin: 5vh auto;
    color: #333;
}