CSS modification to show more of the forms titles in the forms selection popup

This is about the forms selection popup in the BA-Forms 2.3.0.1 backend. I'd like to have more of the forms title visible in the popup that appears when clicking on the "All" field (see attachement). For this, I tried to add some custom CSS, but could not find the a solution so it smoothly works.

Can anyone help me and reply the CSS modifications that will mak the popo up wider so that more of the title will be visible, please?

Thanks, Pete