div#left_menu{
    position:fixed;
    z-index:100;
    width:160px;
    border:1px solid silver;
}

div#left_menu div.accordion {
    /* display:none; */
    background-color: white;
}
div#left_menu div.accordion div.accordion-item:hover {
    background-color: #e7e7e7;
}
div#left_menu div.accordion div.accordion-item a{
    padding-left:10px;
}
div#left_menu div.accordion div.accordion-collapse a{
    padding-left:30px;
}