CSS to adjust vertical spacing of Gravity Forms Fileds

The Blank Slate template works well for my purpose. I just need to adjust the vertical spacing between the gravity fields on the PDF document. I was able to adjust line-height of paragraphs with core_template_styles.php but can’t find where to adjust the pacing for the various GF fields. Where do I add the CSS to control these fields?

https://www.dropbox.com/s/5d7v25gmlfkbwab/Screen%20Shot%202016-07-19%20at%209.23.41%20AM.png?dl=0

Thanks for any advice.

https://wordpress.org/plugins/gravity-forms-pdf-extended/