Store settings has a new setting, Design, with five designs for every page of your Store: Starter, Minimal, Bold, Editorial and Boutique. Each has a drawing of its layout and colours. Bold has a dark background; the others are light.
Your accent colour, fonts, menu, announcement and storefront language apply in every design. Stores keep the Starter design until you choose another.
Fields and labels on the Cart and Checkout now use your Store's colours in every browser, including one set to dark mode.