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

# Design System: Linear — Agent Prompt Guide

## Quick Color Reference

- Primary CTA: Brand Indigo (`#5e6ad2`)
- Page Background: Marketing Black (`#08090a`)
- Panel Background: Panel Dark (`#0f1011`)
- Surface: Level 3 (`#191a1b`)
- Heading text: Primary White (`#f7f8f8`)
- Body text: Silver Gray (`#d0d6e0`)
- Muted text: Tertiary Gray (`#8a8f98`)
- Subtle text: Quaternary Gray (`#62666d`)
- Accent: Violet (`#7170ff`)
- Accent Hover: Light Violet (`#828fff`)
- Border (default): `rgba(255,255,255,0.08)`
- Border (subtle): `rgba(255,255,255,0.05)`
- Focus ring: Multi-layer shadow stack

## Example Component Prompts

- "Create a hero section on `#08090a` background. Headline at 48px Inter Variable weight 510, line-height 1.00, letter-spacing -1.056px, color `#f7f8f8`, font-feature-settings `'cv01', 'ss03'`. Subtitle at 18px weight 400, line-height 1.60, color `#8a8f98`. Brand CTA button (`#5e6ad2`, 6px radius, 8px 16px padding) and ghost button (`rgba(255,255,255,0.02)` bg, `1px solid rgba(255,255,255,0.08)` border, 6px radius)."
- "Design a card on dark background: `rgba(255,255,255,0.02)` background, `1px solid rgba(255,255,255,0.08)` border, 8px radius. Title at 20px Inter Variable weight 590, letter-spacing -0.24px, color `#f7f8f8`. Body at 15px weight 400, color `#8a8f98`, letter-spacing -0.165px."
- "Build a pill badge: transparent background, `#d0d6e0` text, 9999px radius, 0px 10px padding, `1px solid #23252a` border, 12px Inter Variable weight 510."
- "Create navigation: dark sticky header on `#0f1011`. Inter Variable 13px weight 510 for links, `#d0d6e0` text. Brand indigo CTA `#5e6ad2` right-aligned with 6px radius. Bottom border: `1px solid rgba(255,255,255,0.05)`."
- "Design a command palette: `#191a1b` background, `1px solid rgba(255,255,255,0.08)` border, 12px radius, multi-layer shadow stack. Input at 16px Inter Variable weight 400, `#f7f8f8` text. Results list with 13px weight 510 labels in `#d0d6e0` and 12px metadata in `#62666d`."

## Iteration Guide

1. Always set font-feature-settings `"cv01", "ss03"` on all Inter text — this is non-negotiable for Linear's look
2. Letter-spacing scales with font size: -1.584px at 72px, -1.056px at 48px, -0.704px at 32px, normal below 16px
3. Three weights: 400 (read), 510 (emphasize/navigate), 590 (announce)
4. Surface elevation via background opacity: `rgba(255,255,255, 0.02 → 0.04 → 0.05)` — never solid backgrounds on dark
5. Brand indigo (`#5e6ad2` / `#7170ff`) is the only chromatic color — everything else is grayscale
6. Borders are always semi-transparent white, never solid dark colors on dark backgrounds
7. Berkeley Mono for any code or technical content, Inter Variable for everything else
