#sidebar .list-group-item {
    border-radius: 0;
    background-color: #333;
    color: #ccc;
    border-left: 0;
    border-right: 0;
    border-color: #2c2c2c;
    white-space: nowrap;
}

/* highlight active menu */
#sidebar .list-group-item:not(.collapsed) {
    background-color: #222;
}

/* closed state */
#sidebar .list-group .list-group-item[aria-expanded="false"]::after {
    content: " \f0d7";
    font-family: FontAwesome;
    display: inline;
    text-align: right;
    padding-left: 5px;
}

/* open state */
#sidebar .list-group .list-group-item[aria-expanded="true"] {
    background-color: #222;
}
#sidebar .list-group .list-group-item[aria-expanded="true"]::after {
    content: " \f0da";
    font-family: FontAwesome;
    display: inline;
    text-align: right;
    padding-left: 5px;
}

/* level 1*/
#sidebar .list-group .collapse .list-group-item  {
    padding-left: 20px;
}

/* level 2*/
#sidebar .list-group .collapse > .collapse .list-group-item {
    padding-left: 30px;
}

/* level 3*/
#sidebar .list-group .collapse > .collapse > .collapse .list-group-item {
    padding-left: 40px;
}

@media (max-width:48em) {
    /* overlay sub levels on small screens */
    #sidebar .list-group .collapse.in, #sidebar .list-group .collapsing {
        position: absolute;
        z-index: 1;
        width: 190px;
    }
    #sidebar .list-group > .list-group-item {
        text-align: center;
        padding: .75rem .5rem;
    }
    /* hide caret icons of top level when collapsed */
    #sidebar .list-group > .list-group-item[aria-expanded="true"]::after,
    #sidebar .list-group > .list-group-item[aria-expanded="false"]::after {
        display:none;
    }
}

/* change transition animation to width when entire sidebar is toggled */
#sidebar.collapse {
    -webkit-transition-timing-function: ease;
    -o-transition-timing-function: ease;
    transition-timing-function: ease;
    -webkit-transition-property: width;
    -o-transition-property: width;
    transition-property: width;
    -webkit-transition-duration: .2s;
    -o-transition-duration: .2s;
    transition-duration: .2s;
}

#sidebar.collapsing {
    opacity: 0.8;
    width: 0;
    -webkit-transition-timing-function: ease-in;
    -o-transition-timing-function: ease-in;
    transition-timing-function: ease-in;
    -webkit-transition-property: width;
    -o-transition-property: width;
    transition-property: width;

}