Here you go. Among other things, it turns this:
Into this:
.xwikipanelcontents { padding-right: 0px; }
.jstree-xwiki > .jstree-no-dots.jstree-no-icons a.jstree-anchor {
white-space: nowrap;
text-overflow: ellipsis;
overflow: hidden;
width: 100%;
}
.jstree-xwiki > .jstree-no-dots.jstree-no-icons li.jstree-node { padding-left: 10px; }
.skin-flamingo .jstree-xwiki .jstree-clicked {
background-color: #e4e4e4;
font-weight: bold;
}