Change Registration form label and input width

In my registration form ( leadershipexchange.gle.world/index.php?o...vent_id=1&Itemid=150 )  I need to change the form labels and input boxes to be full width. They're using "col-md-3" for the label parent div and "col-md-9" for the input parent div currently. Which file contains these classes that I can change please? I've tried in the /register/ folder in my theme, but I can't find any reference to it. These are for the default fields and the custom fields. 

Thank you!

Hello

What css class you want to change to? You can go to Events Booking -> Configuration, look at CSS Class Mapping tab, add new mappings to change it to the class you want. For example :

- Original CSS Class: col-md-3
- New Cass Class: col-md-6

Then it will change col-md-3 to col-md-6

Regards,

Tuan