Signal 06 of 09 · Nebula Diagnostic Spec v1.0.0

Above-Fold Clarity

Can a visitor understand the offer and next action in the first viewport?

Decision rule

Within the initial viewport a first-time visitor must be able to answer three questions: what is offered, who it is for, and what to do next. A run flags pages where any of these answers requires scrolling or inference.

What the engine inspects

  • ·viewport-height slice of rendered DOM
  • ·headline, subhead, CTA presence in that slice

How to check it yourself

  1. Screenshot the initial viewport on desktop and at 390px mobile width.
  2. Ask whether a stranger could answer three questions from that slice alone: what is offered, who it is for, what to do next.
  3. Any answer that requires scrolling or inference fails the signal.

The engine automates this inspection and attaches measured evidence to every failing condition. A manual pass is not a substitute for the recorded evidence trail, but it should agree with it.

Pass / fail examples

Pass

Offer, audience, and CTA all legible in the first desktop and mobile viewport. Clear.

Fail

First viewport contains only a full-screen illustration and a logo; offer and action require scrolling. Flagged.