Every new UI need maps to one layer in the stack below — from the design-system substrate up to specialized sections. Walk the decision flow before writing code for a new pattern.
Two layers sit below the five, applied ambiently.
Supporting systems (the substrate). Metaobjects (theme_color, text_style, typeface/font, content_width, spacing…), color schemes, and Shopify platform APIs. They apply with zero per-element config: a bare <h2>Your cart</h2> renders per theme configuration without metadata on the element. The bare-tag text_style binding (in utility--css-variables) styles h1–h6; --color-* variables and color-scheme values cascade in.