docs: function () {
              var i, len, page, $page,
                  width, height, left, top, paddingH,
                  state = this.state,
                  viewportWidth = state.viewportDimensions.clientWidth,
                  viewportHeight = state.viewportDimensions.clientHeight;
              // update pages so they are centered (preserving margins)
              for (i = 0, len = this.$pages.length; i < len; ++i) {
                  $page = this.$pages.eq(i);
                  page = state.pages[i];
  
                  if (this.twoPageMode) {
                      paddingH = (i % 2 === 1) ? page.paddingRight : page.paddingLeft;
                  } else {
                      paddingH = page.paddingRight + page.paddingLeft;
                  }
                  width = (page.actualWidth + paddingH) * state.zoomState.zoom;
                  height = (page.actualHeight + page.paddingTop + page.paddingBottom) * state.zoomState.zoom;
  
                  if (this.twoPageMode) {
                      left = Math.max(0, (viewportWidth - width * 2) / 2);
                      if (i % 2 === 1) {
                          left += width;
                      }
                  } else {
                      left = (viewportWidth - width) / 2;
                  }
                  top = (viewportHeight - height) / 2;
                  left = Math.max(left, 0);
                  top = Math.max(top, 0);
                  $page.css({
                      marginLeft: left,
                      marginTop: top
                  });
              }
          }