Thank you both for your help. I had tried formating the import with double and single quotes as well but that didn’t work either.
I think I see the other stylesheets in the source file… assets/css/globals.css, assets/templates/green/style.css, and assets/css/typography1.css are all in the parent folder (green-stimulus). I’m not sure how the child theme style sheet is being referenced twice. Could it be the server not clearing old versions of the file?