.treeview {
  margin: 0;
  padding: 0;
}

.treeview,
.treeview ul {
  list-style-type: none;
}

.treeview ul {
  margin-bottom: 0;
}

.treeview li {
  position: relative;
}

.treeview .item {
  margin-left: 20px;
}

.treeview .box {
  cursor: pointer;
}

.treeview .box::before {
  content: "+";
  color: #fefefe;
  display: inline-block;
  cursor: pointer;
  margin-right: 6px;
}

.treeview .openbox::before {
  content: "−";
}

.treeview .nested {
  display: none;
}

.treeview .nested::before {
  content: " ";
  position: absolute;
  margin-left: -15px;
  border-left: 2px dashed;
  height: calc(100% - 30px);
  overflow: hidden;
}

.treeview .active {
  display: block;
}