Lisa here from the Shopify Social Care Team.
For Shopify built themes, like Supply, the navigations are responsive to how many labels are put in the navigation from the admin. This adjusts the height acordingly which means it's tricky to simply code it to reduce the height. The navigation needs to be responsive on different sized screens and mobile.
Since you're using a Shopify theme, feel free to email firstname.lastname@example.org with screenshots of how much you'd like the navigation reduced. Our themes team can review your request and let you know if this is covered in the free 60 minutes design time!
Best of luck,
- Lisa ?
Thank you for your reply. I understand that they are responsive, but the nav bar just seems so thick with only 4 menu items on it. I'm attaching a picture.
Thanks for providing the screenshot. This is totally understandable why you'd want the navigation a little thinner, especially since it only has 4 items in it. I definitely recommend emailing our main support for a design request since you're using a Shopify theme. It seems likely the team will be able to implement this design change for you.
If you like, once you have emailed email@example.com, let me know your store's myshopify.com URL here and I can retrieve this request and send it directly to the themes team.
Hope this helps!