Hi Nancy
I am using Dreamweaver CS6
Until today I could only use px choice for font selection in CSS rules. That applies to existing rules or any new rules I created.
However, following advice here, I went into the CSS code for that rule, changed Type Font-size from px to %
The rule immediately permitted me to select other versions of font sizes for that rule. The example shown in the screen shot is where I have not yet amended the coding. Maybe you can see that the Type Font-size is greyed out to px only. However, once I go into the rule and amend the code the drop down then permits % and all the other choices for that rule. But for that rule only.
Any new CSS rules the same applies. The new rule offers only px. font size. However, once I change the code manually the rule gets "freed-up"
However, In the properties window at the foot of the screen indicates that I can select % or whatever font measurement I wish. That is new.
From my point of view I have an answer to my question, although it is a sort of work-around.
Best wishes
Peter