بريف صفحة لفريق التصميم

I need a brief for a {{PAGE_TYPE}} page aimed at {{SEGMENT}}.

The one thing this page must achieve: {{GOAL}}

Produce a handoff document with:
1. The page's single message, in one sentence a designer can hold in their head.
2. Section-by-section breakdown: what each section proves, and what the reader believes after it that they did not believe before.
3. For each section, the copy slots needed (headline, body, proof, CTA) with character guidance.
4. The proof elements required, and where each one comes from.
5. The one section to cut first if the page runs long.

Write it so a designer can start without asking me a question.