How to change the display order of webform elements (conditional logic)?

How to change order (weight) of webform elements in conditional logic based on the visibility of other elements?

My webform example, six fields:

1. Open field A? (Checkbox yes/no)

2. Field A is hidden (textfield, hidden because current-page-node-field-a is null)

3. Open field B? (Checkbox yes/no)

4. Field B is hidden (textfield, hidden because current-page-node-field-b is null)

5. Open field C? (Checkbox yes/no)

6. Field C is open (textfield, opened because current-page-node-field-c NOT null)

Now, what I want...

I would like to add conditional rule to field C, so that if it is open, show it sэhigher than field A and field B (i.e. change the weight of the fields).

How to achieve this?