Fix "VH" setting to account for Shopify Menu Bar & Announcement Bar

The “VH” height setting does not work well for the first “hero” banner on a page because of the menu bar (and sometimes announcement bar) that exists on Shopify stores. “100 vh” should be 100% of the screen INCLUDING / FACTORING IN the menu bar. I shouldn’t have to tweak the VH setting to get it correctly “full” screen in this case, it should recognize the announcement bar and that the hero banner is at the top of the page, or there should at least be a setting for this.