How to adjust the login pages with bootstrap? Components used:


Bootstrap 3.7.1. 
Drupal 8


I would like to adjust the size of the login screen (and related screens) to a size of 6 grids. So I think adding the following bootstrap class 

col-md-6 offset-md-3


to 

.block-user-login-block 


will do the trick. I can add this to the block css.

But bootstrap needs to have .row class just before this. How can I easily solve this?
Solved by changing the bootstrap class to

col-md-6 col-md-offset-3