# Swiss Signal - Construction Instructions & AI Prompting Guide
> Version 1.0 - Theme 16 in the catalog - slug `swiss-signal`

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## Table of Contents

1. [Design Philosophy & Core Rules](#1-design-philosophy--core-rules)
2. [Font Law](#2-font-law)
3. [Color Application Rules](#3-color-application-rules)
4. [Border Radius Decision Framework](#4-border-radius-decision-framework)
5. [Shadow & Elevation Rules](#5-shadow--elevation-rules)
6. [Component Construction Guides](#6-component-construction-guides)
7. [Interactive States](#7-interactive-states)
8. [Layout Rules](#8-layout-rules)
9. [Anti-Patterns](#9-anti-patterns)
10. [AI Prompting Guide](#10-ai-prompting-guide)
11. [Pre-Ship Checklist](#11-pre-ship-checklist)

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## 1. Design Philosophy & Core Rules

International style: white page, heavy black rules, one red signal colour and big Archivo headlines.

### The Rules
1. Structure is drawn with 3px black rules, not with shadows or fills.
2. Red (#d90700) is only for the single main action or a critical signal.
3. Headlines are huge, heavy (900), tight and left aligned. Never centred.
4. Layout sits on a visible grid. Align everything to the same left edge.

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## 2. Font Law

Use only Archivo. Fallback stack ends in `system-ui, sans-serif`.

- Display and headings: Archivo, weight 900, tracking -0.03em.
- Body: Archivo.
- Labels: Archivo, uppercase, weight 700.
- Never mix in a font from another system. If a glyph is missing, fall back, do not swap families.

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## 3. Color Application Rules

| Use | Token | Value |
|---|---|---|
| Page | `--ds-color-bg-base` | `#ffffff` |
| Cards | `--ds-color-bg-surface` | `#ffffff` |
| Inputs, wells | `--ds-color-bg-sunken` | `#f2f2f2` |
| Main action | `--ds-color-primary` | `#d90700` |
| Secondary action | `--ds-btn-secondary-bg` | `#111111` |
| Body text | `--ds-color-text-primary` | `#111111` |
| Supporting text | `--ds-color-text-secondary` | `#444444` |

- One main action per view.
- Never type a raw hex or font name in a component. Read the token.
- Semantic colours (success, warning, error, info) are for status only.

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## 4. Border Radius Decision Framework

- Badge or chip: 0px.
- Button or input: 0px.
- Card or modal: 0px.
- Anything else: use the nearest token. Never invent a radius.

---

## 5. Shadow & Elevation Rules

- Cards: `none`.
- Dropdowns: `none`.
- Modals: `none`.
- Focus: `0 0 0 3px #d90700`.
- Do not mix shadow styles from other systems.

---

## 6. Component Construction Guides

**Card:** surface background, 3px border `#111111`, radius 0px, card shadow, padding 24px.

**Button:** pick one variant. Label style `uppercase`, weight 700. Pressed state is `translateY(1px)`.

**Badge:** label style, semantic background, no shadow.

**Table:** header uses `#111111` with `#ffffff` text. Rows separated by border light.

**Form field:** label above, helper text below in muted colour, error replaces helper text.

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## 7. Interactive States

| State | Rule |
|---|---|
| Hover | Primary darkens or lightens one step. Shadow `none` |
| Active | `translateY(1px)` |
| Focus | `0 0 0 3px #d90700`, always visible |
| Disabled | Text `#9a9a9a`, no hover |

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## 8. Layout Rules

- Max content width 1040px, 24px gutters.
- Stack to one column below 768px.
- Keep one primary action per section and align it to the same edge as the heading.

---

## 9. Anti-Patterns

- Do not use shadows, gradients or rounded corners.
- Do not use red for decoration, icons or links.
- Do not centre paragraphs of text.
- Do not hard-code colours, fonts, radii or shadows in components.
- Do not define tokens at `:root`. Everything stays under `[data-ds="swiss-signal"]`.
- Do not mix components from other design systems on the same page.

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## 10. AI Prompting Guide

Paste this at the start of a chat:

> Build the UI with the Swiss Signal design system. Read `design-system.md` and `instructions.md` first. Use only the `--ds-*` tokens under `[data-ds="swiss-signal"]`. Fonts: Archivo. Follow every rule in section 1 of instructions.md. Do not add styles that are not in the token sheet. When unsure, ask before inventing.

Good follow-up prompts:
- "Add a pricing section using only Swiss Signal tokens."
- "Check this page against the Swiss Signal anti-pattern list and fix violations."

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## 11. Pre-Ship Checklist

- [ ] All colours, fonts, radii and shadows come from tokens
- [ ] One main action per view
- [ ] Text contrast is 4.5:1 or better
- [ ] Focus state is visible on every interactive element
- [ ] No rule from section 9 is broken
- [ ] Wrapped in `data-ds="swiss-signal"`