feat: page composition per IA research — section order, tile icons, cross-page coherence

DESIGN.md

@@ -190,12 +190,41 @@ snap is worse than a calm fixed width.
 | Badges | Quiet hairline pill, muted sentence-case text, Galaxy dot on mocks; "Mock — reason"; never removed | REQUIREMENTS §5, NN/g hierarchy |
 | Cards | Cover · title (clamp 3) · desc (clamp 2) · date · read time; no non-differentiating metadata | NN/g metadata |
 | Pagination | Newer/Older + windowed numbers, 44px targets, aria-current | NN/g pagination |
-| Article | Back "← All news"; meta category · author · date · read time; italic muted captions; TOC at ≥3 headings; post-nav | editorial convention |
+| Article | Back "← All news"; h1 → standfirst (description) → meta (category · author · date · read time) → cover → inline TOC → prose; italic muted captions; TOC at ≥3 headings; post-nav | Guardian/BBC anatomy |
 | Forms | Visible labels above fields; placeholders are examples only; buttons start with a verb | GOV.UK forms, NN/g |
 | Login | One line + button + one small-print line; no reassurance prose | auth brevity |
 | Footer | Identity line → Contact · Search · Disclaimer · Privacy · Site settings · Content editor → © line; no implementation talk in UI copy | NN/g footers |
 | Search results | Links lay out as flowing text (mark-safe); date chip; "Press Enter for all results" hint | — |
 
+## Page composition (archetypes)
+
+Every page follows one of three archetypes; a new page picks one instead of
+inventing a section order.
+
+| Archetype | Pages | Order |
+|---|---|---|
+| Portal landing | `/` | Hero (h1 + subtitle + CTA pair + one-line Latest teaser) → Services tiles (Moon) → Latest news 3-up + "All news" (white) |
+| Section landing | `/news`, `/search`, `/proposals`, `/dashboard`, `/support` | Galaxy hero band carrying the h1 + one-line subtitle → single content band (Moon = utility, white = editorial listing) → footer |
+| Document | `/news/<slug>`, `/pages/<slug>` | Back link → h1 → standfirst → meta → cover → inline TOC → prose (→ post-nav on articles); no hero band — the document IS the page |
+
+- Home is task-first (NN/g homepage principles: clear starting points for the
+  top 1–4 tasks — for scientists that's proposals/data/support, not reading
+  news). The hero teaser is the freshness signal (deep-links the newest
+  article); the 3-card section below is the browse layer — different
+  granularity, not redundant.
+- Document order is press anatomy (Guardian/BBC/Reuters): headline →
+  standfirst → byline/meta → lead image → body. The inline TOC sits between
+  lead image and body (Wikipedia/GOV.UK contents position) so the editorial
+  head stays unbroken and the list is adjacent to what it indexes.
+- Back affordances: articles "← All news", static pages "← Home" (footer- and
+  deep-link-reached documents must not be dead ends). Auth (`/login`) is the
+  sole exception to the archetypes: one focused card, no hero, no sections.
+- Service tiles carry a stroke glyph (`.ico` family: currentColor, round caps,
+  aria-hidden; 26px Galaxy) ABOVE the label — never instead of it (NN/g icon
+  usability: icons are ambiguous alone; beside an always-visible label they
+  differentiate otherwise-uniform tiles and speed grid scanning). Glyphs are
+  wayfinding, not decoration — they don't count against the one-accent budget.
+
 ## Do not
 
 - No new hues, tints, or grays — derive via `color-mix` from brand tokens only.