Explain interface

This skill answers how something on the web was built. /explain-interface how the gradient on example.com was built finds the layers producing that gradient and explains what each one contributes.

It explains rather than judges. There is no verdict, because how someone else built their interface is not a finding. Reviewing against a standard is interface-review and better-interface, and exploring alternatives for your own is variant. Name what you find in the vocabulary of the domain skill that owns it, such as better-typography for type or better-colors for palette.

Scope to the question

The question	What you produce	Method
How was this site built?	The frontend: framework and rendering strategy, styling system, component library, tokens, the type, spacing and color systems, motion, breakpoints, how fonts and images are served	read-the-system.md
How was this built?	The layer stack behind one effect, in paint order, with the technique on each layer	find-the-effect.md

Given a named thing, scope to it. A type scale and a token dump are not a longer answer to "how is the gradient built". Pull in a neighbour only where the effect cannot be explained without it, and say why.

Either question can be asked of a screenshot instead of a URL. See From a screenshot, it is a reconstruction.

What you can actually read

How you reach the page decides what you may claim. Say which route you used.

	A scriptable browser	Fetched HTML and CSS
Gives you	What actually paints: computed values, paint order, pseudo-elements, live animations	The source: authored declarations, responsive and state variants, generated utilities, every :root token
Blind to	Any width or state you did not visit	Which rule wins, resolved pixel values and anything injected at runtime