source: branches/stable/templates/grouptree.css@ 302

/*
  Pure CSS collapseable tree for groups, for all browsers but IE
  Adapted (mostly trimmed down) from http://www.thecssninja.com/css/css-tree-menu
  Fails variously in IE < 9, may or may not work in IE 9
*/

ul.grptree {
        padding-left: 40px;     /* hack pthui */
}
li.hassub {
        position: relative;
        margin: 0 0 0 -40px;
        padding: 0;
        list-style: none;
        background: none;       /* hack pthui */
}
li.leaf {
        margin: 0;
        padding: 0 0 0 15px;    /* in px since this is to adjust for a fixed-size image */
}
li.hassub input {
        position: absolute;
        left: 0;
        margin: 0;
        opacity: 0;
        filter:alpha(opacity=0);        /* IE > 6, maybe */
        z-index: 2;
        cursor: pointer;
        height: 1em;
        width: 1em;
        top: 0;
}
li.hassub input + ul {
        background: url('../images/tree_closed.png') 0px -2px no-repeat;
        margin-top: -0.95em;    /* esplain to me, why this not 1em?  O_o */
        padding-top: 0.1em;
        padding-left: 2.25em;   /* ah-HA!  use this to adjust the indent!  watch for neg margin from li.hassub */
        xdisplay: block;
        height: 1em;
}
li.hassub input + ul > li {
        height: 0;
        overflow: hidden;
        margin-left: -14px !important;
}
li.hassub label {
        cursor: pointer;
        display: block;
        padding-left: 15px;     /* in px as it ajusts for fixed-size image */
}
li.hassub input:checked + ul {
        background: url('../images/tree_open.png') 0px 0px no-repeat;
        margin-top: -1.2em;
        padding-top: 1.1em;
        height: auto;
}
li.hassub input:checked + ul > li {
        height: auto;
}