I am trying to define a custom CSS class 'ctr_col' to centre align the contents of  some string columns in a wpDataTable created from a Gravity form. I am then inserting the 'ctrl_col' in the "CSS class(es)" field in the relevant column settings.  However the string is remaining left aligned. Should I be aligning something other than text to centre align 

Please can you advise?

This is an exact paste of what I have put in the settings area: 

table.wpDataTable td.ctr_col {
 text-align: center;
}

Don't worry I've worked it out myself.

I only needed to add the following in the Custom css field on the CUSTOM JS AND CSS within the WPDT settings area:

.ctr_col { text-align: center !important;}

Now I can use that custom CSS class .ctr_col to centre any column.

Hoorah!

Thanks