div#navigation {
    margin-left: 10px;
}

div#navigation ul {
    padding-left: 0px; 
    margin-left: 0px;
    margin-top: 0px;
    list-style-type: none;
}

div#navigation ul li a {
    color: #000;
    text-decoration: none;
    font-weight: bold;
}

div#tree_content {
    margin-top: 40px;
    margin-left: 10px;
    margin-right: 10px;
}