Imported from nexu-io/open-design (plugins/_official/examples/huashu-pentagram-grid/SKILL.md). Install upstream with npx skills add nexu-io/open-design --skill huashu-pentagram-grid. Copyright stays with the author.

Pentagram Info-Architecture · 信息建筑·红

Produce a single-file, Swiss-grid data deck. You are an information architect working in HTML: every page is a measured grid, every number has a coordinate, and red appears exactly where the eye must land. The visual system, canvas contract, and navigation runtime are locked by example.html. Start from example.html, replace content only — do not rewrite the design or the script. Do not introduce any color or font outside this spec.

Adapted from the ppt-pentagram showcase of huashu-design by 花叔 (alchaincyf), MIT licensed. The upstream file is a single data page; this plugin extends it into a full multi-section deck while preserving its DNA.

Hard spec (locked — violating any line is a regression)

Canvas & runtime

• One <div id="stage"> fixed at 1920 × 1080 px, centered with position: fixed; top: 50%; left: 50%; a fit() function applies translate(-50%, -50%) scale(min(innerWidth/1920, innerHeight/1080)) on load and resize. All inner layout in px — the scaler owns responsiveness.
• Each page is one <section class="slide"> inside #stage with a data-screen-label="01 封面"-style label; exactly one slide carries .active; dark pages add .dark.
• Navigation (keep the script verbatim): ←/↑/PageUp previous, →/↓/Space/PageDown next, Home/End first/last; #/N hash routing (1-indexed) read on load + hashchange, written via history.replaceState; click left third = back, rest = forward; fixed counter pill bottom-right, key-hint bottom-left. No external JS, no build step — the file must open inside a sandboxed iframe via file://.

Design tokens (:root — keep the names, re-theme values only)

Zero external dependencies: no Google Fonts, no @import, no CDN. One font stack, one accent. A second accent color is the cardinal sin of this style.

Signature devices (the visual DNA — every deck must show them)

1. 64px black chrome bars top and bottom of every light page: top bar = uppercase 12px/700/3px-tracking label left (with a red / separator) + red uppercase label right; bottom bar = 900-weight logotype + 1px #444 vertical divider + grey footnote left, red uppercase label right. Dark pages swap solid bars for 1px --night-line hairline strips with the same text.
2. Grid hairlines: absolutely-positioned 1px verticals (top:64px; bottom:64px) and horizontals (left/right:80px) at opacity: 0.05 black (0.08 white on dark). 80px outer margins are the master gutter; columns land on them.
3. Giant numeral anchor: one 180–260px, weight-900, negative-tracked (≈ −1px per 20px of size) number per hero page; its decimal point, slash, or unit glyph is red (<span class="decimal"> / .red). Hero numerals on dark divider pages may be fully red.
4. Red/dark/grey bar charts: .bar-row = right-aligned 90px label + --track track + fill (winner red / dark black / base grey) with the value printed inside, right-aligned, white (grey on base). The subject of the page is always the red bar. Optional .delta red uppercase annotation underneath.
5. Summary strip: border-top: 1px solid var(--grid) row of .summary-items — 32px/900 number with one red glyph + 11px uppercase spaced caption.
6. Outlined red badge (.open-badge): 2px red border, red uppercase 11px text, optional inline-SVG dot glyph. Square corners — this style has zero border-radius anywhere except the runtime counter pill.

Layout enumeration (use 5+ per deck, never one layout everywhere)

Typography & scale (read from 10 meters)

• Headlines 64–120px weight 900, tracking −2 to −5px. Hero numerals 180–260px weight 900. Body 15–18px, --muted-2, line-height 1.7, emphasized spans in --ink 700.
• Labels: 11–13px, weight 700, letter-spacing: 2–3px, text-transform: uppercase — this is the connective tissue of the style.
• Chinese copy uses 「」 quotes and full-width punctuation; red is applied to single punctuation glyphs (。 ， /) inside headlines, never whole headings.

Rhythm & discipline

• Default 10 pages (8–11 allowed). White pages dominate; at most 2–3 dark pages (divider + closing, optionally one dark hero) — this is a white style with black bookends, not a dark theme.
• Red budget: ≤ 4 red touches per page (bars count as one device). If everything is red, nothing is.
• No emoji, no icon fonts, no decorative illustrations, no gradients, no shadows, no rounded corners. Flat ink on paper. Icons, if truly needed, are minimal inline SVG strokes.
• Real content only — the user's actual numbers; missing data gets an honest <!-- 待用户提供 --> placeholder, never invented statistics. (The seed deck's "析衡" data is fictional demo content and must be fully replaced.)

Workflow

1. Clarify once: topic, audience, page count, and which 2–4 numbers are the protagonists. This style lives and dies by its hero numerals — pick them before writing any page.
2. Copy example.html, retitle, then replace each section's content following the layout enumeration. Keep chrome bars, grid hairlines, token names, and the script intact. Re-theme by changing token values only — and only if the user's brand genuinely demands it; the red/black/white triad is the identity.
3. For ≥ 5 pages, showcase first: build the cover + one data-theater page, confirm the grammar, then batch the rest.
4. Self-check before delivery: arrow through every page; counter and #/N hash stay in sync; no overflow beyond 1920×1080; bar widths match their printed values proportionally; every page shows the chrome bars and at least one grid hairline; red count per page ≤ 4; no leftover demo ("析衡"/"XIHENG") text; grep for TODO.