Sidebar Icons AddOn

#side-bar .side-block .menu-item > .image {
   -webkit-user-select: none;
   user-select: none;
}
#side-bar .collapsible-block-folded {
    background: none;
}
#side-bar .collapsible-block-folded a.collapsible-block-link {
    margin-left: 0;
}
#side-bar .collapsible-block-folded a.collapsible-block-link::before {
    content: "";
    display: inline-block;
    width: 13px;
    height: 13px;
    margin-right: 2px;
    background: url(http://scp-jp.wdfiles.com/local--files/nav:side/expand.png) 0 0 no-repeat;
    transform: translateY(2px);
}