How do I manually set padding values for a specific page?

I have an index page on Brine that I am trying to set specific padding values for. I need to reduce all the white space between sections, but don't want to implement on a site-wide basis. I know I can do this in the page-level CSS, I just don't know how. Any help?

Page: https://mustard-purple-5te8.squarespace.com/messages Password: stmarkstest

Thank you!

@richardsonad Use Page ID :) Each page will have different ID. See how to find Page ID: https://beaverhero.com/squarespace-how-to/#HowtoFindPageID

body#collection-5d26514417521b0001ef7a8a .Index-page-content {
   padding-top: 0;
   padding-bottom: 0;
}

Thanks! added the