tStep = this.slides[lastIdx - 1].$$('.incremental > *').length;
    this.setCursor(lastIdx, lastStep);
  }

  Dz.toggleView = function() {
    this.html.classList.toggle("view");

    if (this.html.classList.contains("view")) {
      $("section[aria-selected]").scrollIntoView(true);
    }
  }

  Dz.setSlide = function(aIdx) {
    this.idx = aIdx;
    var old = $("section[aria-selected]");
    var next = $("section:nth-of-type("+ this.idx +")");
    if (old) {
      old.removeAttribute("aria-selected");
    