.tree
{
    text-align:left;
    font-size:2vw;


}

.border_tree
{
    border-right: 2px solid gray;
}


.tree_node
{
    margin-left:10px;

}
.tree_node_title:hover
{
    color:black;
    background-color:white;
}
.tree_entry
{
    margin-left:10px;
}
.tree_entry:hover
{
    background-color:white;
}

.closed::before
{
    content:"[+]";
}
.opened::before
{
    content:"[-]";
}