WYSIWYG that support Em unit (in addition to PX) ?

[aasdsdf]

Hey,

I'm using version community 1.7.0.2, I notice that HTML editor (WYSIWYG) that supports em unit.
the editor that comes with my version support only PX .

The main reason is to add support to new design that will be responsive and we want that the employees won't touch the code at all.

The problem Is when we use CMS page and product page (not in the gallery)

Thanks

[aasdsdf]

What's happens if I leave the dimensions blank?