igation tree structure */
    #trees {
        padding: 0 1rem;
    }

    .tree-toggle {
        display: none;
    }

    .tree-toggle:checked + .tree-toggle-label + .subtree {
        display: block;
    }

    .tree-toggle-label {
        display: block;
        padding: 0.75rem 1rem;
        margin: 0.25rem 0;
        border-radius: 6px;
        font-weight: 600;
        cursor: pointer;
        transition: all 0.2s ease;
    }

    .tree-toggle-label:hover {
        background-color: rgba(0, 0, 0, 0.0