# Swiss Signal - Complete Design System
> Version 1.0 - Theme 16 in the catalog - slug `swiss-signal`

---

## Table of Contents

1. [System Overview](#1-system-overview)
2. [CSS Custom Properties - Master Token Sheet](#2-css-custom-properties--master-token-sheet)
3. [Color Palette](#3-color-palette)
4. [Typography System](#4-typography-system)
5. [Spacing System](#5-spacing-system)
6. [Border Radius System](#6-border-radius-system)
7. [Shadow & Elevation System](#7-shadow--elevation-system)
8. [Component Specifications](#8-component-specifications)
9. [Layout & Grid System](#9-layout--grid-system)
10. [Animation & Transition Tokens](#10-animation--transition-tokens)
11. [Z-Index System](#11-z-index-system)
12. [Breakpoints](#12-breakpoints)
13. [Icon System](#13-icon-system)
14. [State Definitions](#14-state-definitions)

---

## 1. System Overview

**Design Language:** Swiss Signal
**Mode:** Light
**Typeface:** Archivo
**Personality:** International style: white page, heavy black rules, one red signal colour and big Archivo headlines.
**Best Suited For:** Editorial product pages, transit and civic tools, portfolios, data-heavy reports, signage-like UI

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

---

## 2. CSS Custom Properties - Master Token Sheet

All tokens are scoped under `[data-ds="swiss-signal"]`. Nothing is defined at `:root`. The same sheet ships as `tokens.css` in this system's folder.

```css
/*
 * Swiss Signal - scoped design-system tokens (Theme 16 in catalog).
 */

[data-ds="swiss-signal"] {
  --ds-color-bg-base: #ffffff;
  --ds-color-bg-surface: #ffffff;
  --ds-color-bg-sunken: #f2f2f2;
  --ds-color-bg-secondary: #f2f2f2;
  --ds-color-bg-overlay: rgba(17,17,17,0.55);

  --ds-color-primary: #d90700;
  --ds-color-primary-hover: #bf0600;
  --ds-color-primary-active: #a90500;
  --ds-color-primary-fg: #ffffff;

  --ds-color-text-primary: #111111;
  --ds-color-text-secondary: #444444;
  --ds-color-text-tertiary: #595959;
  --ds-color-text-muted: #595959;
  --ds-color-text-disabled: #9a9a9a;
  --ds-color-text-inverse: #ffffff;

  --ds-color-border-light: #111111;
  --ds-color-border-medium: #111111;
  --ds-color-border-strong: #111111;

  --ds-color-success: #1b7441;
  --ds-color-success-bg: #d7f2e0;
  --ds-color-warning: #8a5700;
  --ds-color-warning-bg: #fff0cc;
  --ds-color-error: #c0262d;
  --ds-color-error-bg: #fde3e4;
  --ds-color-info: #1d5fbf;
  --ds-color-info-bg: #dce9fb;

  --ds-font-display: "Archivo", system-ui, sans-serif;
  --ds-font-body: "Archivo", system-ui, sans-serif;
  --ds-font-label: "Archivo", system-ui, sans-serif;
  --ds-label-transform: uppercase;
  --ds-label-tracking: 0.12em;
  --ds-label-weight: 700;
  --ds-heading-tracking: -0.03em;
  --ds-heading-weight: 900;

  --ds-radius-badge: 0px;
  --ds-radius-sm: 0px;
  --ds-radius-md: 0px;
  --ds-radius-lg: 0px;
  --ds-radius-xl: 0px;
  --ds-radius-full: 9999px;

  --ds-border-width: 3px;

  --ds-shadow-card: none;
  --ds-shadow-dropdown: none;
  --ds-shadow-modal: none;
  --ds-shadow-focus: 0 0 0 3px #d90700;
  --ds-shadow-btn-hover: none;

  --ds-btn-text-transform: uppercase;
  --ds-btn-letter-spacing: 0.06em;
  --ds-btn-font-weight: 700;
  --ds-btn-active-transform: translateY(1px);
  --ds-btn-secondary-bg: #111111;
  --ds-btn-secondary-text: #ffffff;
  --ds-btn-secondary-border: #111111;
  --ds-btn-secondary-hover-bg: #0f0f0f;
  --ds-btn-outline-text: #111111;
  --ds-btn-outline-border: #111111;
  --ds-btn-outline-hover-bg: #f2f2f2;
  --ds-btn-outline-hover-text: #111111;

  --ds-table-header-bg: #111111;
  --ds-table-header-text: #ffffff;
  --ds-table-header-border-bottom: 3px solid #111111;
  --ds-table-container-radius: 0px;
  --ds-table-container-border: 3px solid #111111;

  --ds-focus-ring: 0 0 0 3px #d90700;

  --ds-ease-standard: linear;
  --ds-duration-fast: 0ms;
  --ds-duration-base: 100ms;
  --ds-duration-slow: 150ms;
}
```

---

## 3. Color Palette

### 3.1 Core Colors

| Role | Value |
|---|---|
| Page background | `#ffffff` |
| Surface | `#ffffff` |
| Sunken | `#f2f2f2` |
| Secondary surface | `#f2f2f2` |
| Primary action | `#d90700` |
| Primary text on action | `#ffffff` |
| Accent / secondary button | `#111111` |
| Accent text | `#ffffff` |
| Text primary | `#111111` |
| Text secondary | `#444444` |
| Text muted | `#595959` |
| Border light | `#111111` |
| Border strong | `#111111` |

### 3.2 Semantic Colors

| Status | Foreground | Background | Contrast |
|---|---|---|---|
| Success | `#1b7441` | `#d7f2e0` | 4.9:1 |
| Warning | `#8a5700` | `#fff0cc` | 5.4:1 |
| Error | `#c0262d` | `#fde3e4` | 4.9:1 |
| Info | `#1d5fbf` | `#dce9fb` | 5.0:1 |

### 3.3 Contrast Checks

All pairs below meet WCAG AA (4.5:1) for normal text.

| Pair | Colors | Ratio |
|---|---|---|
| Body text | `#111111` on `#ffffff` | 18.9:1 |
| Secondary text | `#444444` on `#ffffff` | 9.7:1 |
| Muted text | `#595959` on `#ffffff` | 7.0:1 |
| Primary button label | `#ffffff` on `#d90700` | 5.3:1 |
| Accent button label | `#ffffff` on `#111111` | 18.9:1 |
| Table header | `#ffffff` on `#111111` | 18.9:1 |

---

## 4. Typography System

### 4.1 Font Families

| Role | Family | Usage |
|---|---|---|
| Display | Archivo | Headlines, hero titles, buttons |
| Body | Archivo | Body copy, form fields |
| Label | Archivo | Uppercase labels, table headers |

### 4.2 Type Scale

| Token | Size | Weight | Tracking | Use |
|---|---|---|---|---|
| Display | 48-64px | 900 | -0.03em | Hero title |
| H1 | 36px | 900 | -0.03em | Page title |
| H2 | 28px | 900 | -0.03em | Section title |
| H3 | 20px | 900 | -0.03em | Card title |
| Body | 16px | 400 | 0 | Paragraphs |
| Label | 12px | 700 | 0.12em | Eyebrows, badges (uppercase) |

### 4.3 Google Fonts Import Block

```css
@import url("https://fonts.googleapis.com/css2?family=Archivo:wght@400;700;900&display=swap");
```

The same URL is loaded by `app/design-systems/fonts.ts`.

---

## 5. Spacing System

Base unit: 4px. Use only these steps.

| Token | Value |
|---|---|
| space-1 | 4px |
| space-2 | 8px |
| space-3 | 12px |
| space-4 | 16px |
| space-6 | 24px |
| space-8 | 32px |
| space-12 | 48px |
| space-16 | 64px |

Component padding: card 20px, button 10px 20px (md), input 10px 14px, badge 2px 10px.

---

## 6. Border Radius System

| Element | Radius |
|---|---|
| Badge | 0px |
| Small controls (checkbox) | 0px |
| Buttons, inputs | 0px |
| Cards, modals | 0px |
| Large panels | 0px |
| Avatars, switches | 9999px |

Border width: 3px.

---

## 7. Shadow & Elevation System

| Level | Value |
|---|---|
| Card | `none` |
| Dropdown | `none` |
| Modal | `none` |
| Focus | `0 0 0 3px #d90700` |
| Button hover | `none` |

---

## 8. Component Specifications

### 8.1 Buttons
- Primary: background `--ds-color-primary`, label `--ds-color-primary-fg`. Hover `#bf0600`, active `#a90500`.
- Secondary: background `#111111`, label `#ffffff`.
- Outline: transparent, border `#111111`, label `#111111`.
- Label style: `uppercase` text, weight 700, tracking 0.06em.
- Active (pressed): `transform: translateY(1px)`.

### 8.2 Form Inputs
Surface background, 3px border `#111111`, radius 0px. Focus uses the focus shadow. Error border `#c0262d`.

### 8.3 Labels
Font Archivo, uppercase, weight 700, tracking 0.12em, colour `#595959`.

### 8.4 Card / Surface
Background `#ffffff`, border 3px `#111111`, radius 0px, shadow card.

### 8.5 Badge
Pill or 0px radius, label style, semantic backgrounds from section 3.2.

### 8.6 Checkbox, Radio and Switch
Checked fill `#d90700`, mark `#ffffff`. Switch track uses border strong when off.

### 8.7 Table
Header background `#111111`, header text `#ffffff`. Container border `3px solid #111111`, radius 0px.

### 8.8 Dropdown Panel
Surface background, border 3px `#111111`, dropdown shadow, item hover uses `#f2f2f2`.

---

## 9. Layout & Grid System

| Container | Max width |
|---|---|
| Narrow (forms, articles) | 640px |
| Default | 1040px |
| Wide (dashboards) | 1280px |

12-column grid, 24px gutters on desktop, 16px on mobile.

---

## 10. Animation & Transition Tokens

| Token | Value |
|---|---|
| Easing | `linear` |
| Fast | 0ms |
| Base | 100ms |
| Slow | 150ms |

Animate colour, transform, opacity and shadow only. Never animate layout properties.

---

## 11. Z-Index System

| Layer | Value |
|---|---|
| Base | 0 |
| Sticky header | 10 |
| Dropdown | 20 |
| Modal backdrop | 40 |
| Modal | 50 |
| Toast | 60 |

---

## 12. Breakpoints

| Name | Min width |
|---|---|
| sm | 640px |
| md | 768px |
| lg | 1024px |
| xl | 1280px |

Page padding: 16px below md, 24px at md, 32px at lg and up.

---

## 13. Icon System

Use Lucide icons at 16, 20 or 24px, stroke 2px (1.5px for Swiss Signal if the type is light). Icon colour follows text colour. Never use filled multi-colour icons.

---

## 14. State Definitions

| State | Treatment |
|---|---|
| Hover | Darker or lighter primary (see 8.1), shadow `none` |
| Active | `translateY(1px)` |
| Focus | `0 0 0 3px #d90700` |
| Disabled | Text `#9a9a9a`, no shadow, cursor not-allowed |
| Error | Border `#c0262d`, message in the same colour |
| Success | Border `#1b7441` |