Add the feature to set the font size (and other value) as percentage, based on a "root" style. For example: create a "root" paragraph style with the size font set to 10 pt. Create a new paragraph style "first" based on "root" style and set the font size value to 110%. (=11pt). If the the font size of "root" style change, automatically change the font dimensioni in "first" style proportionally. Like the in the CSS language.