Change grouped tags into a checkbox style

snippet.css

.collection aside nav.tags ul {
    max-height: 300px;
    overflow: scroll;
}
.collection aside nav.tags li {
    display: block;
}
.collection aside nav.tags li a {
    background: transparent;
    box-shadow: none;
    padding: 4px 0;
    display: block;
}
.collection aside nav.tags li a:before {
    display: inline-block;
    content: '';
    height: 12px;
    width: 12px;
    position: relative;
    top: 2px;
    margin-right: 4px;
    border: 1px solid #000;
}
.collection aside nav.tags li.active a:before {
    background: #d99819;
}
.collection aside nav.tags li.active a {
    background: none;
    color: #000;
    box-shadow: none;
}
.collection aside nav.tags li.active.close a:after {
    display: none;
}