<!-- SPDX-License-Identifier: MIT -->
<!-- SPDX-FileCopyrightText: 2025-2026 Marcus Quinn -->

# Startup Bold — Typography Rules

## Font Families

| Role | Stack |
|------|-------|
| Sans | `'Plus Jakarta Sans', 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif` |
| Mono | `'JetBrains Mono', 'Fira Code', 'SF Mono', monospace` |

## Type Scale

| Role | Font | Size | Weight | Line Height | Letter Spacing | Notes |
|------|------|------|--------|-------------|----------------|-------|
| Display | Sans | 64px | 800 | 1.05 | -0.035em | Landing heroes, pricing headlines |
| H1 | Sans | 48px | 700 | 1.1 | -0.03em | Page titles |
| H2 | Sans | 36px | 700 | 1.15 | -0.025em | Section headings |
| H3 | Sans | 28px | 600 | 1.2 | -0.02em | Subsection headings |
| H4 | Sans | 22px | 600 | 1.25 | -0.01em | Card titles |
| H5 | Sans | 18px | 600 | 1.3 | -0.005em | Group labels, small headings |
| Overline | Sans | 13px | 600 | 1.4 | 0.06em | Category labels (UPPERCASE) |
| Body Large | Sans | 18px | 400 | 1.65 | -0.006em | Lead paragraphs |
| Body | Sans | 16px | 400 | 1.6 | -0.006em | Primary reading text |
| Body Small | Sans | 14px | 400 | 1.5 | 0 | Captions, secondary info |
| Label | Sans | 13px | 500 | 1.4 | 0.02em | Form labels, buttons, metadata |
| Code | Mono | 14px | 400 | 1.6 | 0 | Code snippets, technical content |

## Typography Principles

- Headings are heavy (700–800) to command attention — this is not a delicate system
- Negative letter-spacing on headings tightens the visual weight as size increases
- Body text at 400 weight provides clear contrast against bold headings
- Use uppercase overlines sparingly to categorise sections
- One typeface family (Plus Jakarta Sans) creates cohesion — variation comes from weight and size
