I have tried as many ways as i can possibly think off to change the size of text fields but nothing seems to work. setting the size in the xml form set-up does nothing even going in and editing the jdom for that field type and specifically defining it to be 10px does nothing. Can anyone Help?

I guess its a css override but i can't see where its coming from.

Cheers

you can create style classes to their fields!
Whenever you create an element in your form,it acquired the ID Class (jform_) + the name that you set out on table. Sample:
id = "jform_adress"
id = "jform_city"
....

Now you can create the style for ids.
Sample:

You can also take a espesífico class name for your forms through of the Online Generator. This way you can create a generic style classes for all elements of this form

It is a Bootstrap problem.

When it uses such classes : spanX, of input-xxxxx (ex: input-medium), then the with is dynamic and respect a grid.

Solution :
Remove those css classes, and then JDom param will be effective.

EDIT : The solution of neoneper is OK also.
it is using '!important' word, so be carefull with browser compatibilities.

Note that !important should only be used in particular cases.
So the best is to use my solution, I think. But still, I say, two solutions should work.

I have the same problem, and I understand how to create a whole new set of CSS for my forms.

But I can see that this is not just CSS, the html has cols and rows set which are not the setting I have saved in J-Cook.

I am looking for a solution so that I don't have to go and edit every form in every view each time i update my component.

I did not understand the method described by admin
Which CSS classes?