/**
 * Framework starts from here ...
 * ------------------------------
 */

.tree,
.tree ul {
    margin: 0 0 0 1em; /* indentation */
    padding: 0;
    list-style: none;
    color: #369;
    position: relative;
}

.tree ul {
    margin-left: .5em
}
/* (indentation/2) */

.tree:before,
.tree ul:before {
    content: "";
    display: block;
    width: 0;
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    border-left: 1px solid;
}

.tree li {
    margin: 0;
    padding: 0 1.5em; /* indentation + .5em */
    line-height: 2em; /* default list item's `line-height` */
    font-weight: bold;
    position: relative;
}

.tree li:before {
    content: "";
    display: block;
    width: 10px; /* same with indentation */
    height: 0;
    border-top: 1px solid;
    margin-top: -1px; /* border top width */
    position: absolute;
    top: 1em; /* (line-height/2) */
    left: 0;
}

.tree li:last-child:before {
    background: white; /* same with body background */
    height: auto;
    top: 1em; /* (line-height/2) */
    bottom: 0;
}