Adding a border around a floating section in Brine template

I have implemented custom code to float an index section between two other sections in the Brine template. This is on a few different index pages, but specifically for the sake of this example, we'll look at the "Journal" page, and the floating section is titled "Journal Float" (creative, I know).

I added a plain white banner background to give it some oomph, but am curious if there is anyway to add a border around the entire floating section to help it stand out a bit more using CSS.

Website
Password: weddings
Page: Journal, floating section at the top titled "Journal Float"

Any ideas on best way to go about this?

@bpurnell Add to Home > Design > Custom CSS

section#journal-float {
   border: 10px solid #ff0000;
}

See how to insert CSS: https://beaverhero.com/squarespace-how-to/#HowtoInsertCustomCSS