docs: function () {
              // vertical stuff
              var state = this.state,
                  zoom = state.zoomState.zoom,
                  zoomedWidth,
                  docWidth;
  
              zoomedWidth = Math.floor(state.widestPage.totalActualWidth * zoom);
  
              // use clientWidth for the doc (prevent scrollbar)
              // use width:auto when possible
              if (zoomedWidth <= state.viewportDimensions.clientWidth) {
                  docWidth = 'auto';
              } else {
                  docWidth = zoomedWidth;
              }
  
              this.$doc.css({
                  width: docWidth
              });
          }