.toolbar .toolbar-icon::before {
    position: absolute;
    top: 0;
    left: 0.6667em;
    display: block;
    width: 20px;
    height: 100%;
    content: "";
    background-color: transparent;
    background-repeat: no-repeat;
    background-attachment: scroll;
    background-position: center center;
    background-size: 100% auto;
  }

  .toolbar-icon-tul-helpdesk-link-helpdesk::before {
    background-image: url(/core/modules/toolbar/css/../../../misc/icons/787878/questionmark-disc.svg);
  }