edit

front/static/document.js

@@ -177,7 +177,7 @@ var Document =
         var b = w/self.width;
         if (self.left) {
             if (w - self.width > 10) {
-                var z = 100-(100/b) + self.zoom;
+                var z = (100/b) + self.zoom;
                 $(self.option.reader).css('zoom', z + '%');
             }