CSS on a Grid Form

I’ve searched around, but could not find a response, so here it goes

I have a gridview form (that displays on a master detail form)

Working on the grid view application when I try to change the width of the field and alignment (on the CSS of the field under display settings), nothing happens.

However if I change the font, it does work.

My form is not correctly sized field wise (some data does not fit and breaks in 2 lines, etc) so I need to adjust field sizes.

Played around with several options, without any luck.

Help will be welcome.

Thanks in advance.

*** UPDATE

The field sizes I managed to understand now. Obviously we have to adjust also the label size.

However centering the field does not work.