Corpus

Swiss Poster Design System

A design system based on Swiss poster design from the 1950s through 1980s: grotesque type at extreme scales, layouts that break the grid, overlapping layers, diagonal energy, and cropped forms. Draws on Weingart, Troxler, Odermatt & Tissi, Hofmann, and Ruder.

Output contract for web/UI tasks

When the user asks for a page, component, landing page, or Tailwind/UI styling, return implementable HTML/Tailwind/CSS. Do not satisfy a web/UI task with a standalone SVG poster unless the user explicitly asks for an SVG, print asset, or static poster file.

Hard gates before final output:

• Start from an explicit grid grid-cols-12 structure, then let selected elements escape it.
• Use exactly one accent hue per project (default #C8102E). Opacity variants of that hue are allowed; extra accent hues, purple SaaS gradients, and multi-accent palettes are not.
• Make scale contrast extreme: pair viewport-scale text-[clamp(...)] display type with text-[11px] labels; target 10×+ size ratio and leading-[0.85], tighter custom leading, or leading-none at display scale.
• Prevent horizontal scroll. Any section with bleed, negative margins, absolute breakouts, wide vw elements, or cropped type needs overflow-hidden, overflow-x-hidden, or overflow-clip on the wrapper.
• Check the 320px boundary: default to col-span-12, fluid clamp() type, reduced offsets (md: and up for aggressive negative margins), no fixed-width elements that force sideways scroll, and 44px minimum touch targets.
• For dense poster HTML, annotate the reading contract: put data-critical="title", data-critical="body", data-critical="date", or data-critical="cta" on essential text, and keep decorative anchors aria-hidden="true"/pointer-events-none.
• For historically grounded, source-heavy, image-heavy, or diagrammatic posters, leave non-visible implementation evidence in markup: data-reference for the embodied historical move, data-source/data-beat for source-ledger items, and data-encoding/data-variable for real diagram mappings. These attributes are for auditability; do not show eval/provenance labels as visible poster copy.
• Respect non-design boundaries: do not apply this skill to Switzerland geography, tax/legal residency, Swiss German translation, or other non-poster meanings of “Swiss.” If this skill is loaded anyway for a non-design Swiss query, explicitly note that Swiss Poster design does not apply and answer normally only if appropriate. If the user asks for clean corporate Swiss minimalism and explicitly rejects poster drama, restrain the composition instead of forcing this style.

Dramatic poster recipe

The inspiration set at https://swiss.ziki.boo/inspiration shows that drama usually comes from one dominant graphic event, not from sprinkling many effects. For each hero or major poster section, choose the event first, then code around it.

Communication before spectacle. Historic Swiss posters were public communication: legible from the street, fast to parse, and memorable because the big form carried the message. Drama fails if the title, date, core offer, or CTA becomes hard to read. Use collisions and crops on the anchor or secondary layers; keep the primary reading path clear.

Protected reading zone heuristic

Historic Swiss poster drama separates text as image from text for reading. Müller-Brockmann's arcs, Hofmann's figure/ground forms, Matter's photomontage, and Weingart's typographic disruption can be severe because the event name, place, date, or public instruction still has a protected path. The poster may attack the grid; it must not attack comprehension.

Before placing any dramatic anchor, classify layers:

Layer	Purpose	May be cropped/obscured?	Implementation rule
Critical reading	title, date/time, CTA, safety warning, core claim, essential explanation	No	Put on a quiet field, highest content z-index (relative z-30/z-40), readable size/leading, strong local contrast against the actual backing
Support reading	metadata, labels, coordinates, index numbers, captions	Slightly, if still parseable	Tiny but crisp; keep away from high-noise textures
Graphic image	cropped word, giant number, route line, object, photo fragment, ring, hazard shape	Yes	aria-hidden, pointer-events-none, lower z-index (z-0/z-10/z-20), opacity/clip/crop allowed

Use the quiet-field test: every critical text block needs an uninterrupted rectangle of calm tone behind it. If a route, slash, ring, photo edge, ghost word, or giant letter crosses that rectangle, one of these must happen:

1. move/crop the graphic so it misses the rectangle;
2. send the graphic behind the text at low opacity (text-stone-900/[0.06], opacity-10) so it becomes texture;
3. put the text on a solid light/dark/accent field with padding and higher z-index;
4. invert deliberately with mix-blend-difference only after checking the whole word remains readable.

Hard rule: body copy and CTAs never sit directly on top of high-contrast mega-type, route lines, diagrams, or photos. Titles may collide only when the collision is the concept and the complete title remains readable in three seconds. Do a final street test: at a glance, can someone read the title, the key fact/date, and the action before admiring the geometry?

Contrast-channel discipline

Use WCAG/similar accessibility work only as measurement physics, not as aesthetic law. Extract three lessons: contrast is local to the pixels/field behind the text; two high-contrast signals in the same rectangle mask each other; critical information needs first claim on the reader's attention. Do not import the baggage: no bland compliance look, no ban on tiny microtype, no ban on crops/overlap/inversion, and no assumption that every layer must be equally readable.

Do not lower the poster's contrast. Allocate it. Swiss poster drama should stay brutal: black/stone fields, hard orange/red slabs, severed routes, giant glyphs, and violent figure/ground are allowed. The rule is that maximum contrast cannot be unresolved competition.

Use three channels:

Channel	What it does	Contrast rule
Critical signal	title, date, CTA, core body/safety claim	Dominant contrast event inside its reading zone; no competing line/photo/glyph through the glyphs
Dramatic signal	photo, route slash, giant numeral, object, diagram, cropped word	May be maximum contrast, but must route around, sit behind, or become the field for critical text
Texture signal	halftone, grid, contour, ghost type, dense labels	Can pass behind copy only when demoted: low opacity, low spatial frequency, or tone-matched

If critical text and a dramatic anchor share a zone, make one of these explicit moves:

• cut silence: carve a hard stone-50/stone-950/accent rectangle through the graphic and put the copy there;
• route around: bend/stop the route line, slash, or diagram before it enters the reading zone;
• send behind: keep the graphic but demote it to texture (opacity-5, opacity-10, or text-stone-900/[0.06]);
• make the field the drama: put black text on an orange slab, white text on a black slab, or stone text on a white cutout so the reading zone is itself a graphic event;
• separate z-indexes: critical text relative z-40, dramatic image aria-hidden="true" pointer-events-none z-0/z-10, texture below both.

Never solve readability by making the whole poster polite. Solve it by assigning contrast channels so the title/date/body/CTA win locally while the rest of the field stays severe.

Artifact fidelity before style

A Swiss poster is an edited public artifact, not a style transfer skin. Before composing, build a private source ledger and make the poster answer it.

Failure to avoid	Historically grounded correction	Implementation carrier
Generic slogans replacing real source content	International Style communication discipline: objective facts, names, dates, places, sequence, hierarchy	Preserve required entities; mark dense items with data-source or data-beat; never invent missing names/talks
Photos used as wallpaper texture	Herbert Matter photomontage: image fragments are subject/place/evidence/metaphor	Give each image a role (data-image-role="place", "person", "evidence", "sequence"); crop around the role, not randomly
Fake diagrams/arrows/nodes	Müller-Brockmann/Ruder systems thinking: marks encode rhythm, order, relation, or measured structure	Add data-encoding="source variable → visual variable"; remove any node/line/axis that does not encode a fact
Microtype as lorem-text noise	Ruder typographic function: small type still communicates	Microtype must be credits, source notes, coordinates, schedule, index, or captions — not fake texture
One-size portrait template	Grid as method, not template	Match the requested/baseline artifact: poster, one-page recap, landscape, thread sequence, matrix, map, or specimen
Prompt-shaped artifacts	Public poster copy, not implementation notes	Never print dimensions, hex codes, “single accent,” “current skill,” “source material,” “brief,” “generated,” or eval/provenance labels
Clipped mandatory content	Public-viewing discipline	Essential ledger items must remain inside the canvas and unobscured; crop only graphic/support layers

If a prompt provides tweets, images, historic facts, or a baseline artifact, preserve its information structure before applying style: count the beats, keep real names/places/dates, choose which items are title/support/microtype, and only then decide the visual anchor. If you cannot verify an exact source fact, do not hallucinate specificity; use a broader true label or state the missing input outside the artwork.

Historical period and genre selection

Do not accidentally anchor every poster in late-1960s/1980s black-white-red typographic disruption. Swiss poster history is broader than Weingart/Troxler energy. Pick a lineage and genre because it fits the subject, then let that choice constrain color, image handling, typography, grid behavior, and material surface.

Lineage / period	Best fit	Use	Avoid
Sachplakat / object poster (1900s–1930s influence)	Products, artifacts, tools, food, single technical object	one isolated object/silhouette, near-clinical product facts, quiet background, direct name	giant type violence, fake diagrams
Travel / photomontage / lithographic poster (1930s–1950s)	places, journeys, civic destinations, image stories	saturated but disciplined color, cropped photographs/illustration, overprint, paper/grain, place as hero	treating photos as wallpaper or UI cards
Zurich International Typographic Style (1950s–1960s)	public notices, schedules, institutions, education	restrained asymmetric grid, clear hierarchy, objective facts, small number of rules	expressive chaos or decorative microtype
Basel / Hofmann figure-ground (1950s–1960s)	theatre, civic warning, conceptual tension	severe black/white mass, point-line-plane, 2–3 contrast axes, quiet drama	clutter, many simultaneous effects
Geigy / scientific systems (1950s–1970s)	science, pharma, data, protocols, taxonomies	specimen/matrix/plate, measured labels, data-to-form mapping, restrained color	generic route diagrams or SaaS dashboard panels
Matter-style photomontage	editorial/photo-rich source material	authored crop, scale juxtaposition, duotone/overprint, captions with roles	full-bleed photo as background texture
Weingart / New Wave typography (1970s–1980s)	typography, publishing, rebellion, fractured systems	one controlled rupture, type as image, offset layers with hierarchy intact	using chaotic type for every subject
Troxler / performance rhythm	music, festivals, live performance	optical rhythm, repeated marks, surprise, pulse, event-specific energy	same line/ring field on non-musical subjects
Contemporary Swiss cultural poster	modern cultural/tech hybrids	conceptual image, expressive but source-specific system, print-process awareness	generic web-brutalist poster kit

Use non-visible audit markers when helpful: data-lineage="geigy-scientific", data-period="1950s-zurich", data-genre="object-poster", data-print-process="lithographic-overprint", data-contrast="large-small". These must reflect real layout decisions. Do not show the markers as poster copy.

Specific anti-collapse rules:

• Palette breadth: one accent still applies, but it need not be red/orange. Travel may choose lake blue, alpine green, ochre, or sky cyan; scientific posters may use muted analytical color; theatre may use black/white with a restrained accent.
• Typographic violence budget: cropped mega-type is one lineage, not the default. Object, travel, scientific, and Zurich-style posters may use quieter type if image/object/data is the anchor.
• Grid invisibility: grid-cols-12 is construction scaffolding; the final poster should feel proportioned, not like a web dashboard. Avoid rounded cards, CTA modules, feature panels, and browser UI patterns unless the subject is explicitly UI.
• Material process: choose a print surface when relevant — overprint, halftone, duotone, misregistration, ink trap, lithographic grain, screenprint slab, paper tone — without making texture obscure critical copy.
• Diagram restraint: diagrams are not a default Swiss motif. Use them only for systems/data subjects; theatre, travel, product, and manifesto prompts often need image, object, or figure-ground instead.
• Restraint as drama: Hofmann/Ruder restraint can be more Swiss than maximal collision. Choose 2–3 contrast axes and suppress unrelated effects.
• Genre breadth: ask whether the poster is a travel placard, object poster, scientific plate, public notice, concert poster, theatre sheet, typographic specimen, editorial photomontage, or contemporary cultural poster before coding.

Rendered poster proof, not metadata compliance

Invisible attributes are audit hooks, not achievement. A poster that says data-lineage="geigy-scientific" but looks like a Cloudflare event diagram has failed. The rendered image must prove the claim.

Before final output, do a visual proof pass:

• Visual grammar proof: if the claimed lineage is travel, object, Geigy/scientific, theatre, or photomontage, the dominant form must visibly match that lineage without reading attributes.
• Readable-at-image proof: title, date/key fact, CTA/body must be visible in the screenshot, inside the canvas, not hidden by crop, and not dependent on zoom.
• Source-support readability: source-bearing support copy is not exempt just because it is smaller than the headline. If a line preserves a real fact such as “run locally via CLI,” every word must remain readable at image scale or the fact should move to a protected/quiet field.
• No split-field text loss: critical text must not straddle a light/dark or image/field boundary unless each side deliberately flips color or the whole line sits on a solid backing. z-index does not fix black text crossing a black field.
• Source-fidelity proof: the visible poster preserves required names, dates, places, sequence beats, source images, or measured facts; attributes cannot compensate for missing public content.
• Real poster proof: the composition should read as a print artifact at thumbnail and full scale, not as a compliant HTML layout with labels.

Avoid UI/product language unless the subject is UI

Most posters are not landing pages. Avoid reflexive web-language artifacts:

• CTA-button stacks, feature cards, dashboard panels, pricing-table rows, “learn more” modules, and product-marketing blocks.
• Labels like “recap,” “index,” “fig,” “system,” “channel,” or “route” when they are not real source content.
• Rounded cards, soft shadows, button groups, nav-like headers, SaaS feature matrices, and app-dashboard grids.

A call to action can exist, but it should feel like a poster instruction (Reserve seats, Book the night train, Vote Sunday, Bring a demo) rather than a web button module unless the task is explicitly a UI.

Source websites often contain navigation/button copy (View documentation, Get started, Read the docs, Open GitHub). Do not automatically promote those labels into the poster CTA. Treat them as web chrome unless the user explicitly asks for a web page. For a print/poster artifact, either omit the CTA or derive a poster-native instruction from the subject and source facts.

Typography lineage matters

Swiss poster typography is not one Helvetica-like voice. IBM Plex Sans is a practical open fallback for modern grotesk work, not a history eraser and not the default answer for every era. Choose a typographic stance by lineage before choosing a font file:

Lineage	Typographic stance	Open implementation proxy
Sachplakat / object poster	sparse direct product name, custom/commercial wordmark, fewer sizes; object carries the drama	IBM Plex Sans or Barlow Condensed for labels; hand-built/CSS-treated display word
Travel / lithographic	destination lettering may be condensed, painted, serifed, or poster-lettered; image/color carries more than type violence	Barlow Condensed, IBM Plex Serif, Georgia, or custom letter spacing/outline treatment
Photomontage / Matter	type integrates with image crops through scale, diagonal placement, overprint, and captions	grotesk or condensed sans plus authored photo/type masks
Zurich / International Style	neo-grotesk rationalism, clean weights, tight hierarchy, Helvetica/Neue Haas/Univers/Akzidenz-like proportions	IBM Plex Sans, Hanken Grotesk, Helvetica Neue/Arial/system-ui
Basel / Hofmann-Ruder	restrained grotesk, strong spacing, severe hierarchy, generous negative space	IBM Plex Sans/Hanken Grotesk with careful tracking and fewer weights
Geigy / scientific	narrow grotesk/mono/specimen labels, measured tables, controlled captions, technical plates	Barlow/Barlow Condensed, IBM Plex Mono, small caps/tracked labels
Weingart / New Wave	disrupted spacing, fragments, halftone/type-as-image; only when subject warrants rupture	grotesk fragments, extreme tracking, transforms, layered copies
Troxler / contemporary cultural	expressive rhythm, illustration/type fusion, event-specific display lettering	custom CSS lettering, condensed/display sans, or image-led type treatment

Treat commercial historical names as references, not required web fonts. Use system fallbacks where necessary, but vary family category, width, case, spacing, and role so every poster does not feel like the same IBM Plex tech artifact. If the subject predates or rejects International Style, do not force a clean neo-grotesk grid merely because it looks “Swiss.”

Color discipline can be richer than one red accent

The default one-accent rule is anti-slop, not anti-history. Use strict one-accent when the subject has no better palette or when the output risks AI gradient slop. But some Swiss lineages need disciplined multi-tone systems:

• travel/lithographic posters may use 2–3 flat inks plus paper tone;
• scientific/Geigy plates may use muted analytical colors to separate variables;
• civic/political posters may use party/signal colors when source-grounded;
• photomontage may use duotone/overprint pairs.

If using more than one hue, make it a limited print palette (data-palette="three-flat-inks"), not a gradient rainbow. Every hue must have a role: place, variable, warning, party, route, or ink overprint.

Image authorship

Do not merely place images. Author them like poster material:

• crop around the meaningful subject, not the center of the file;
• use scale juxtaposition, angle, mask, duotone, overprint, or halftone;
• caption or index images when they carry source evidence;
• make one image fragment the dominant argument when the prompt is photo-led;
• avoid rounded thumbnails unless the brief is explicitly UI.

Academic literature cautions

Design-history scholarship treats “Swiss Graphic Design” as a contested national label, not a single style. Use that humility in the artwork:

• Do not collapse the canon. Müller-Brockmann, Hofmann, Ruder, Matter, Weingart, Troxler, Geigy, tourism, object posters, schools, printers, clients, awards, and collectors are different histories, not interchangeable Swiss garnish.
• Public infrastructure matters. Swiss posters were shaped by fixed formats, billposting systems, printers, exhibition furniture, public reading distance, and city space. The result should feel like public display matter, not a landing page.
• Client and institution matter. A poster is an interface between a source and a public: event, venue, client, sponsor, route, product, institution, and date are material, not filler.
• School labels are shortcuts. “Basel,” “Zurich,” and “Swiss Style” simplify messy institutions and practices. Use them only to select concrete methods; never print them as proof.
• Typography is production history. Letterpress, lithography, photomontage, phototypesetting, and digital type imply different type behavior. Choose type by era/process/subject.
• Scripts are not texture. Non-Latin or unfamiliar writing systems must be meaningful, accurate, and readable; never use them as exotic visual noise.

Historical grounding is embodied, not named

Designer names are not decoration. A visible label saying “Weingart / Hofmann / Matter” does not make a poster historically grounded. Translate the reference into a concrete compositional move:

Historical source	Embodied move	Modern carrier	Common fake version
Josef Müller-Brockmann / concert posters	Rhythm made visible through arcs, repetition, score-like intervals, disciplined public info	data-reference="muller-brockmann-rhythm", concentric/radial systems, repeated rules, strict metadata path	Random rings behind generic title
Armin Hofmann / Basel figure-ground	Severe black/white mass, point-line-plane tension, image/shape as subject	data-reference="hofmann-figure-ground", hard fields, geometric abstraction, deliberate negative space	Bland card with black rectangle
Herbert Matter / photomontage	Cropped image fragments, scale juxtaposition, overprint, place/action as image	data-reference="matter-photomontage", masked/cropped assets with captions/roles	Full-bleed photo used as wallpaper
Emil Ruder / typography	Type hierarchy, spacing, legibility, small type with function	data-reference="ruder-typographic-function", real captions, measured line length, disciplined microtype	Tiny decorative pseudo-data
Wolfgang Weingart	Disrupted type that still has hierarchy	data-reference="weingart-controlled-disruption", one typographic rupture, offset columns, rule breaks with readable path	Chaotic overlaps everywhere
Niklaus Troxler	Music/performance as rhythm, optical vibration, poster-specific surprise	data-reference="troxler-rhythm", repeated marks/pulses tied to event energy	Same line field on every subject
Odermatt & Tissi	Bold commercial clarity, edge pressure, witty type/image relation	data-reference="odermatt-tissi-commercial-clarity", direct offer, massive product/name, sharp asymmetric crop	Generic Swiss corporate minimalism

Use one historical move, not a museum collage. The move must fit the subject and change the layout. If the designer/reference names were removed, the historical logic should still be visible.

Choose by subject, not by default

Do not reuse the same “dark right field + red bar + cropped word + rings/lines” recipe for every prompt. Pick the archetype whose visual logic comes from the subject:

Subject / message	Better semantic archetype	Avoid
Product, object, artifact	Object poster: isolated cutout/silhouette, one extreme crop, tiny product facts	Abstract rings unless the product is circular/rhythmic
Transit, logistics, location	Route/map poster: paths, nodes, transfer points, coordinates, directional arrows	Decorative line fields that do not encode routes
Report, dashboard, scientific/technical system	Data/diagram poster: axis, matrix, table, bars, schematic, measured labels	Fake chart garnish or generic “big number”
Typography, writing, publishing	Typographic specimen: glyph, baseline grid, x-height, letterform crop, type scale	Photo collage or arbitrary dates
Travel, editorial, portfolio image story	Photomontage: multiple cropped image fragments, overprint, scale juxtaposition	Rounded image cards or single documentary thumbnail
Civic, safety, warning	Scale juxtaposition: oversized hazard vs. small vulnerable figure, clear warning text	Vague abstract geometry that hides the message
Music/performance	Rhythm poster: repetition, pulse, syncopation, waves, score-like structure	Giant date unless the date is the point

The same principle can unfold into many posters: first translate the subject into a visual grammar, then apply grid, scale, crop, microtype, and figure/ground tension.

Every dramatic section needs all five carriers:

1. Dominant anchor with meaning: one cropped word, giant numeral/date, oversized circle/ring, hard color field, or cropped photo fragment occupying roughly 35–70% of the first viewport/section. It must relate to the content, not be arbitrary decoration.
2. Edge pressure: the anchor is pinned to, sliced by, or bleeding past at least one frame edge. Use overflow-hidden, whitespace-nowrap, -ml-[0.06em], -translate-x-*, -right-*, or clip-path deliberately.
3. Microtype/data layer: 2–4 tiny metadata clusters (text-[11px] tracking-widest uppercase) for real dates, index numbers, locations, coordinates, or labels. These make the large move feel intentional.
4. Hard figure/ground contrast: large stone-900/stone-50 fields, split backgrounds, mix-blend-difference, or accent slabs. Drama can come from black/white mass even when the accent is sparse.
5. Graphic system: geometry, repetition, rhythm, or image treatment beyond a decorative rule — concentric rings, translucent circle stacks, diagonal bars, line fields, dot matrices, repeated words, masked photos, or halftone overlays.

Choose one archetype per section:

Archetype	Use when	Required move
Cropped-word poster	A concept or product name can become the image	One word at clamp(6rem,18vw,24rem), cropped by an edge, with tiny labels nearby
Giant-date/numeral poster	Events, reports, launches, versioned products	Date/number occupies 40%+ of section; content becomes a small grid of metadata
Split-field crossover	Need immediate value contrast	Light/dark halves with display type crossing the boundary via mix-blend-difference
Geometric-anchor poster	Abstract/technical/cultural subject	One oversized circle/ring/bar/triangle is the subject, not ornament
Masked-photo poster	A photo is available	Photo is high-contrast, grayscale/duotone, cropped as a shape, overprinted with type/fields
Rhythm/texture poster	Need motion or music/data energy	Repeating lines/dots/words create optical vibration behind restrained copy
Stacked-collage poster	Dense story or multiple assets	Hard-edged layers overlap with explicit z-10/z-20/z-30 and no soft shadows

Avoid the timid middle: a centered heading, a paragraph, three rounded cards, and a small accent line is Swiss-flavored web minimalism, not a dramatic poster. Avoid the opposite failure too: unreadable pileups, random giant dates, decorative microtype that does not communicate, or repeating the same motif because it worked once.

Six Principles

1. Grid as launchpad. Start with a 12-column grid, then let key elements escape it. Oversized type, images, and color blocks should break column boundaries, overlap neighbors, or bleed off the viewport edge. The grid exists so the breakout has meaning.
2. Extreme scale contrast. Place 20rem display type next to 11px labels. A single word can fill the viewport width. The tension between massive and tiny is the hierarchy. Never settle for moderate size differences.
3. Overlap and layer. Elements should collide — text over images, type over type, color blocks overlapping content. Use relative/absolute positioning, negative margins, and z-index stacking to create depth. Collision belongs to graphic/support layers; critical reading text gets a protected quiet field and higher z-index.
4. Bleed and crop. Let elements escape their containers. Type cropped by the viewport edge, images that extend past the layout, color blocks that run off-screen. A composition that's cut off implies it continues beyond the frame.
5. One accent, used boldly. Each project gets exactly one accent color, but where the International Style uses it sparingly, poster style uses it in large, confident fields — full-width bands, oversized shapes, dramatic backgrounds.
6. Tension over comfort. Asymmetric whitespace, unexpected element placement, rotated text, diagonal compositions. The layout should feel dynamic and slightly unresolved, not settled and safe.

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Anti-Slop

Adapted from Impeccable — https://impeccable.style/slop/. "Slop" is the look of an interface no one decided on: the reflexive default chosen because it was easy. This system is slop-resistant by construction, but the defaults still tempt. Every gradient, glow, blur, rotation, and font must be a choice you could defend. If you can't say why it's there, delete it.

Never ship these reflexively:

• No AI palette. No purple/violet gradients, no cyan-on-black. Stone + one accent only.
• No gradient text, no reflexive glow. Flat fills. A glow is allowed only when it is the poster's actual subject, never as polish.
• No pure #000/#fff. Use stone-950 / stone-50.
• No reflexive font monoculture. Use an approved lineage proxy: neo-grotesk, condensed, serif/display, mono/technical, or custom lettering. Avoid Inter, Roboto, Geist, Space Grotesk, Plus Jakarta Sans, and the same IBM Plex Sans treatment on every poster.
• Monospace must earn its place. Mono is for code, data, IDs, and metadata — not decoration.
• No card slop. No identical icon-tile feature-card grids, cards-in-cards, pill buttons, soft shadows, or accent stripes taped to one side of a box.
• No prompt/provenance leakage as visible copy. Do not print dimensions (840 × 1200), hex codes, “single accent,” “current skill,” “source material,” “brief,” “generated,” “prompt,” “audit,” oracle/eval labels, or implementation instructions unless the user explicitly asked for process documentation outside the artwork.
• Not everything centered. Asymmetric, flush-left body. It is still a bug if it fails AA contrast, has cramped padding, or is justified.

Verify with:

npx impeccable detect <file-or-url>

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Typography

Font strategy: choose a family category for the lineage, then use available web/system fonts as proxies. IBM Plex Sans remains the safe open neo-grotesk fallback; it is not the universal Swiss poster voice.

<link rel="preconnect" href="https://fonts.googleapis.com">
<link href="https://fonts.googleapis.com/css2?family=Barlow+Condensed:wght@400;600;700&family=Barlow:wght@400;500;700&family=Hanken+Grotesk:wght@400;500;700&family=IBM+Plex+Mono:wght@400;500&family=IBM+Plex+Sans:ital,wght@0,100;0,300;0,400;0,500;0,600;0,700;1,300;1,400&family=IBM+Plex+Serif:wght@400;600;700&display=swap" rel="stylesheet">

Approved implementation families by role:

Role	Font category	Good open/system proxies	Use when
Neo-grotesk sans	rational grotesk	IBM Plex Sans, Hanken Grotesk, Helvetica Neue, Arial, system-ui	Zurich/Basel grid, public notices, institutions
Condensed sans	narrow/display grotesk	Barlow Condensed, Barlow	travel labels, object posters, Geigy labels, compressed metadata
Serif/display	editorial or lithographic proxy	IBM Plex Serif, Georgia	travel/lithographic or historic placards when image/color leads
Mono/technical	measured labels/code/data	IBM Plex Mono, ui-monospace	scientific plates, code/framework posters, axes, source ledgers
Custom lettering	treated word/image rather than font choice	CSS transforms, outlines, masks, extreme tracking, hand-built SVG/text shapes only when appropriate	Sachplakat wordmarks, Troxler/contemporary cultural posters, New Wave fragments

Do not use a broader font palette as decoration. The font category must follow the poster’s era, subject, and image grammar.

Type scale — poster range:

The poster style uses a wider range of sizes than the International Style, and the gaps between levels are deliberately extreme.

Role	Tailwind	Weight	Line height	Notes
Mega	text-[clamp(6rem,15vw,20rem)]	font-bold or font-thin	leading-[0.85]	Viewport-scale type. One word or short phrase.
Display	text-7xl md:text-8xl lg:text-9xl	font-light or font-bold	leading-none	Section anchors
H1	text-5xl md:text-6xl	font-light	leading-tight	Page titles
H2	text-4xl	font-light tracking-tight	leading-snug	Section headings
H3	text-2xl	font-normal	leading-snug	Subsections
Body	text-base font-normal	font-normal	leading-relaxed	max-w-[60ch]
Small	text-sm font-normal	font-normal	leading-relaxed	max-w-[60ch]
Caption	text-xs tracking-widest uppercase	font-normal	leading-normal	Labels, metadata
Mono	font-mono text-sm	font-normal	leading-relaxed	Code, data
Label	text-[11px] tracking-widest uppercase	font-medium	leading-none	Smallest text

Key differences from International Style, when the lineage calls for type-as-image:

• Bold or thin display type is allowed. font-bold and font-thin (100) can create dramatic weight contrast, but object, travel, scientific, and Ruder/Hofmann restraint may need quieter weights.
• Extreme size jumps are one tool, not a universal law. A 20rem heading next to 11px labels is right for cropped-word/New-Wave/event posters; object/travel/scientific posters may let image, object, or diagram be the anchor.
• Tight leading at large sizes. Display type can use leading-[0.85] or leading-none; do not let tight type obscure public information.
• Type as image is lineage-specific. At poster scale, letterforms can become graphic elements, but not every Swiss poster should become a giant IBM Plex word crop.

---

Color System

Stone palette (light mode → dark mode)

Role	Light	Dark	Tailwind
Page background	stone-50	stone-950	bg-stone-50 dark:bg-stone-950
Surface / card	stone-100	stone-900	bg-stone-100 dark:bg-stone-900
Subtle surface	stone-200	stone-800	bg-stone-200 dark:bg-stone-800
Border	stone-200	stone-800	border-stone-200 dark:border-stone-800
Primary text	stone-900	stone-50	text-stone-900 dark:text-stone-50
Secondary text	stone-900/70	stone-50/70	text-stone-900/70 dark:text-stone-50/70
Tertiary text	stone-900/40	stone-50/40	text-stone-900/40 dark:text-stone-50/40

Opacity hierarchy

To de-emphasize text, reduce opacity — never change the hue.

Full presence:   text-stone-900          (primary)
Softer:          text-stone-900/70       (secondary, labels)
Quiet:           text-stone-900/40       (tertiary, captions)
Ghosted:         text-stone-900/20       (disabled, placeholder)

Dark mode: replace stone-900 with stone-50. The opacity values stay identical.

Accent color

Each project uses one accent color. Default is Swiss poster red.

Name	Hex	Tailwind arbitrary
Swiss Red (default)	#C8102E	[#C8102E]
Cobalt	#003B8E	[#003B8E]
Golden	#F0B429	[#F0B429]
Forest	#2D6A4F	[#2D6A4F]

Poster-style accent usage — bolder than International Style:

Full field:  bg-[#C8102E]                Full-width bands, large shapes, hero backgrounds
Overlay:     bg-[#C8102E]/80            Translucent overlay on images or sections
Muted:       bg-[#C8102E]/60            Hover states, secondary elements
Tint:        bg-[#C8102E]/20            Background washes, card tints
Ghost:       bg-[#C8102E]/10            Very subtle tints

The poster style permits large accent surfaces. A full-width red band, a half-page accent block, or accent type at mega scale are all correct. The International Style limited accent to 10–15% of visual surface; poster style can push to 30–40% when the composition demands it.

---

Grid & Breakout

Base unit: 8px. Spacing is multiples of 8, but elements are free to escape the grid.

The grid is a starting point

<!-- Standard 12-column grid — the foundation -->
<div class="grid grid-cols-12 gap-4 md:gap-8">
  <div class="col-span-12 md:col-span-8">...</div>
  <div class="col-span-12 md:col-span-4">...</div>
</div>

Breaking the grid (the goal)

Elements escape their grid cells using negative margins, absolute positioning, and overflow:

<!-- Type that bleeds left out of its container -->
<div class="max-w-6xl mx-auto px-8 relative">
  <h1 class="text-[clamp(6rem,15vw,20rem)] font-bold leading-[0.85] -ml-[0.04em] text-stone-900 dark:text-stone-50">
    PLAKAT
  </h1>
</div>

<!-- Element that escapes its column into the neighbor -->
<div class="grid grid-cols-12 gap-8">
  <div class="col-span-5 relative">
    <div class="absolute -right-24 top-0 w-64 h-64 bg-[#C8102E]"></div>
  </div>
  <div class="col-span-7">...</div>
</div>

<!-- Full-bleed accent band that ignores the container -->
<div class="bg-[#C8102E] -mx-[100vw] px-[100vw] py-16">
  <div class="max-w-6xl mx-auto">...</div>
</div>

Overlap patterns

<!-- Text overlapping a color block -->
<div class="relative">
  <div class="w-2/3 h-64 bg-[#C8102E]"></div>
  <h2 class="absolute -bottom-8 right-0 text-7xl font-bold text-stone-900 dark:text-stone-50">
    Gestaltung
  </h2>
</div>

<!-- Stacked layers with offset -->
<div class="relative">
  <div class="bg-stone-200 dark:bg-stone-800 p-12 ml-16 mt-16">Content</div>
  <div class="absolute top-0 left-0 w-32 h-32 bg-[#C8102E]"></div>
</div>

---

Image, Geometry & Texture

Images and shapes must behave like poster subjects, not decorative assets.

<!-- Cropped high-contrast photo block with overprint -->
<section class="relative overflow-hidden bg-stone-50 text-stone-900">
  <div class="grid grid-cols-12 gap-4 md:gap-8 min-h-[80svh]">
    <div class="col-span-12 md:col-span-7 relative overflow-hidden bg-stone-900">
      <img src="/photo.jpg" alt="" class="absolute inset-0 h-full w-full object-cover grayscale contrast-150 mix-blend-screen opacity-80" />
      <div class="absolute inset-y-0 right-0 w-1/3 bg-[#C8102E]/80 mix-blend-multiply"></div>
    </div>
    <div class="col-span-12 md:col-span-5 relative p-6 md:p-10">
      <p class="text-[11px] tracking-widest uppercase text-stone-900/50">Basel / 1962 / Fig. 04</p>
      <h2 class="mt-8 -ml-[0.08em] text-[clamp(5rem,14vw,16rem)] font-bold leading-[0.8] tracking-tighter">PHOTO</h2>
    </div>
  </div>
</section>

<!-- Repetition layer: line field / dot matrix / concentric rings -->
<div class="absolute inset-0 pointer-events-none text-stone-900/[0.08]"
  style="background-image: repeating-linear-gradient(90deg, currentColor 0 1px, transparent 1px 8px)"></div>
<div class="absolute -right-[20%] -bottom-[30%] h-[70vw] w-[70vw] rounded-full border-[10px] border-[#C8102E]"></div>

Use grayscale, contrast-125/contrast-150, object-cover, rectangular masks, mix-blend-multiply, mix-blend-screen, or mix-blend-difference to turn photography into graphic material. Avoid rounded image cards and documentary thumbnail grids.

---

Rotation & Diagonal Energy

Rotated elements create movement and break the horizontal/vertical monotony:

<!-- Rotated section label -->
<span class="text-xs tracking-widest uppercase text-stone-900/40 -rotate-90 origin-left">
  Section 01
</span>

<!-- Diagonal accent bar -->
<div class="w-full h-2 bg-[#C8102E] -rotate-3 scale-110 origin-center"></div>

<!-- Rotated display type as background texture (8–12% opacity minimum) -->
<div class="absolute -rotate-12 text-[12rem] font-bold text-stone-900/[0.10] dark:text-stone-50/[0.10] select-none pointer-events-none">
  POSTER
</div>

---

Responsive Design

Every layout must work at 320px and 1440px. The poster drama scales — it doesn't disappear on mobile.

Breakpoint strategy:

Prefix	Width	Use for
(none)	0px+	Mobile — single column, but still dramatic scale
sm:	640px+	Large phones — overlaps begin to appear
md:	768px+	Tablets — 2-col layouts, full overlap compositions
lg:	1024px+	Desktop — full poster compositions, maximum scale contrast

Mobile poster rules:

• Mega type scales down but stays dominant: text-5xl sm:text-7xl md:text-8xl lg:text-[12rem]
• Overlaps simplify: stack vertically, reduce offsets
• Bleeds still work: full-width accent bands remain full-width
• Rotation reduces: rotate-0 md:-rotate-3
• Grid breaks simplify: negative margins reduce on small screens

Fluid type pattern:

<!-- Poster-scale fluid type -->
<h1 class="text-[clamp(3rem,12vw,16rem)] font-bold leading-[0.85] tracking-tight">
  ZÜRICH
</h1>

---

Dark Mode

Use Tailwind's media strategy (respects system preference automatically):

// tailwind.config.js
darkMode: 'media'

Every color token has a dark: variant. See the stone palette table above. Never use bg-black or bg-white — always use stone scale.

Poster sections with inverted backgrounds are common: a bg-stone-900 dark:bg-stone-50 section inside a light page creates dramatic contrast without relying on dark mode.

---

Gotchas

• The grid must exist before you break it. Every layout starts with grid grid-cols-12. Breakout elements use negative margins, absolute positioning, or overflow to escape — they don't ignore the grid entirely.
• Scale contrast must be extreme. If your largest and smallest text are within 3× size difference, you're still in International Style territory. Aim for 10×+ (e.g., 12rem heading / 11px label).
• Overlap needs a clear layer order. Every overlapping composition must have a deliberate z-10, z-20, z-30 stacking. Random overlap looks like a bug.
• Bleed needs clipping on the parent. Escaped elements must not cause horizontal scroll — that is a hard failure, not an acceptable poster effect. Apply overflow-hidden, overflow-x-hidden, or overflow-clip to the section/page wrapper and reduce negative margins on mobile.
• Bold at display sizes, light at body. font-bold / font-thin are for mega/display type only. Body text stays font-normal. This is the opposite of the International Style's "never bold" rule.
• Rotation is seasoning, not the meal. One or two rotated elements per section maximum, and each must reinforce a chosen axis (vertical edge, diagonal slash, radial anchor). Random rotation feels gimmicky.
• Accent fields can be large. Full-width bands, half-page blocks, oversized shapes — poster style embraces large accent surfaces that the International Style would forbid.
• No border-radius on structural elements. The poster style is still rectilinear. No rounded-lg, no pills. rounded-none or at most rounded-sm.
• Never bg-white or bg-black. Use bg-stone-50 / bg-stone-950.
• One accent per project. Even with bolder usage, the discipline of a single accent remains: one hue plus opacity, not red plus blue plus purple, and no gradient palette masquerading as an accent.
• No centered SaaS composition. A centered hero stack plus equal feature cards is a failure unless a dominant cropped anchor or hard field disrupts it.
• No illegible drama. The dominant anchor may be cropped, but the primary title, essential metadata, and CTA must remain readable. If overlap reduces comprehension, move the overlap to a secondary layer.
• No AI tells by reflex. No purple/cyan gradients, gradient text, decorative glow, overused fonts, soft shadows, rounded card grids, or monospace-as-decoration. Run npx impeccable detect to verify.
• Touch targets minimum 44px. All interactive elements must remain usable despite the dramatic compositions.
• Every layout must work on mobile. Poster drama scales down gracefully. Overlaps simplify, mega type shrinks (but stays dominant), bleeds remain.

---

When to read reference files

Task	File
Full color token table, CSS custom properties, dark mode details	references/design-system.md
Tailwind component patterns: buttons, cards, nav, forms, poster compositions	references/components.md
Paste-ready tailwind.config.js and CSS @theme block	references/tailwind-config.md
Designer research, key works, source URLs	references/research.md
Applying this system to an existing page, audit checklist	references/prompting.md