.mlm-tree {
    list-style: none;
    margin-left: 20px;
}
.mlm-tree li {
    margin: 6px 0;
}
.mlm-node {
    padding: 4px 8px;
    border: 1px solid #ccc;
    border-radius: 4px;
    display: inline-block;
    background: #f9f9f9;
}