.taxonomy-tree, .taxonomy-tree ul {
    list-style-type: none;
    position: relative;
}

.taxonomy-tree ul {
    padding-left: 20px;
}

.taxonomy-tree li {
    padding: 2px 0 2px 20px;
    position: relative;
}

/* Connector lines */
.taxonomy-tree li::before, .taxonomy-tree li::after {
    content: '';
    position: absolute;
    left: 0;
}

/* Horizontal line */
.taxonomy-tree li::before {
    border-top: 1px solid #ccc;
    top: 12px;
    width: 15px;
    height: 0;
}

/* Vertical line */
.taxonomy-tree li::after {
    border-left: 1px solid #ccc;
    height: 100%;
    width: 0;
    top: -6px;
}

.taxonomy-tree > li:first-child::after {
    top: 12px;
}

.taxonomy-tree li:last-child::after {
    height: 18px;
}