---
version: alpha
name: Substack
description: Light design system extracted from substack.com (DOM-true values, Emblematic extractor 0.2.0, 2026-11-12).
colors:
  background: "#FFFFFF"
  outline: "#0000001A"
  on-surface: "#363737"
  on-surface-variant: "#777777"
  primary: "#FF6719"
  bg-marketing-green: "#2F6D5D"
  utility-black: "#000000"
  dark-bg-secondary: "#232525"
  color-9: "#0000004D"
  color-10: "#C8C8C8"
  color-11: "#9F7F62CC"
  color-12: "#B0876BCC"
  color-13: "#034B96CC"
  color-14: "#848483CC"
  color-15: "#64A48CCC"
  color-16: "#A88461CC"
  on-primary: "#FFFFFF"
  background-dark: "#FFFFFF"
  on-surface-dark: "#FFFFFF"
typography:
  display-lg:
    fontFamily: Cahuenga
    fontSize: 32px
    fontWeight: 500
    lineHeight: 1.24
  body-md:
    fontFamily: SF Pro (system-ui)
    fontSize: 15px
    fontWeight: 400
    lineHeight: 1.4
  body-sm:
    fontFamily: SF Pro (system-ui)
    fontSize: 13px
    fontWeight: 400
    lineHeight: 1.4
  label-md:
    fontFamily: SF Pro (system-ui)
    fontSize: 15px
    fontWeight: 600
    lineHeight: 1.333
rounded:
  sm: 4px
  md: 8px
  lg: 12px
  full: 9999px
spacing:
  xxs: 4px
  xs: 6px
  sm: 8px
  md: 12px
  lg: 16px
  xl: 20px
  2xl: 24px
  3xl: 32px
  base: 4px
components:
  button-primary:
    backgroundColor: "{colors.primary}"
    textColor: "{colors.background}"
    rounded: "{rounded.md}"
    padding: 0px
    height: 40px
    typography: "{typography.label-md}"
  button-secondary:
    backgroundColor: "#161718"
    textColor: "#EEEEEE"
    rounded: "{rounded.md}"
    padding: 0px
    height: 32px
    typography: "{typography.label-md}"
  card:
    rounded: "{rounded.lg}"
    padding: 32px
  input:
    backgroundColor: "{colors.background}"
    rounded: "{rounded.lg}"
    padding: 0px
    height: 40px
---

# Substack

> Extracted from [https://substack.com/](https://substack.com/) on 2026-11-12 by Emblematic. Every value below was read from the rendered DOM (computed styles, `document.fonts`, and the fonts Chrome actually used to paint text), not estimated from pixels. When the YAML front matter and this prose disagree, the YAML wins. Copy values from this file exactly; don't transcribe them from memory. Don't copy logos, imagery, illustrations or marketing copy.

## Overview

Substack uses a light canvas (#FFFFFF) with a palette led by #FF6719. Type is set in **SF Pro (system-ui)**, **Cahuenga** (display), with 15px body text. Layout: fluid container, none-detected navigation, 1 sections. Built with react, cloudflare.

## Colors

Area-weighted from painted backgrounds, text and borders on the 1440px light capture. Roles are inferred from usage (largest background, most text, interactive fills). Every hex is an exact computed value; a role marked *unverified* is a best guess that has not passed review, so its canonical token (e.g. `primary`) is left out of the front matter.

| Token | Hex | OKLCH | Role | Share of paint | CSS variable |
|---|---|---|---|---|---|
| `background` | `#FFFFFF` | 1 0 0 | bg | 51.1% | `--cover_bg_color` |
| `outline` | `#0000001A` (on bg `#E6E6E6`) | 0 0 0 | border | 40.4% | `--color-utility-detail` |
| `on-surface` | `#363737` | 0.336 0.001 197.1 | text | 1.6% | `--color-fg-primary` |
| `on-surface-variant` | `#777777` | 0.569 0 0 | muted | 0.54% | `--color-fg-secondary` |
| `primary` | `#FF6719` | 0.698 0.201 42.2 | accent | 0.38% | `--color-accent` |
| `bg-marketing-green` | `#2F6D5D` | 0.489 0.069 173.9 | other | 0.81% | `--color-bg-marketing-green` |
| `utility-black` | `#000000` | 0 0 0 | other | 0.81% | `--color-utility-black` |
| `dark-bg-secondary` | `#232525` | 0.262 0.003 197 | other | 0.69% | `--color-dark-bg-secondary` |
| `color-9` | `#0000004D` (on bg `#B3B3B3`) | 0 0 0 | other | 0.34% | — |
| `color-10` | `#C8C8C8` | 0.833 0 0 | other | 0.25% | — |
| `color-11` | `#9F7F62CC` (on bg `#B29981`) | 0.62 0.057 63.6 | other | 0.22% | — |
| `color-12` | `#B0876BCC` (on bg `#C09F89`) | 0.656 0.064 55.6 | other | 0.22% | — |
| `color-13` | `#034B96CC` (on bg `#356FAB`) | 0.42 0.138 255.5 | other | 0.22% | — |
| `color-14` | `#848483CC` (on bg `#9D9D9C`) | 0.613 0.001 106.4 | other | 0.41% | — |
| `color-15` | `#64A48CCC` (on bg `#83B6A3`) | 0.668 0.076 168.2 | other | 0.20% | — |
| `color-16` | `#A88461CC` (on bg `#B99D81`) | 0.639 0.066 65.4 | other | 0.20% | — |

Declared brand/accent tokens: `--color-chat-outgoing-bg-primary` = `#0076FF` (declared, not painted on this page).

Contrast: text on background 11.94:1, muted text 4.48:1, accent 2.91:1.

Gradients in use: `linear-gradient(rgba(0, 0, 0, 0), rgba(0, 0, 0, 0.3))`; `linear-gradient(rgba(84, 69, 63, 0.75), rgba(84, 69, 63, 0.75)), none`.

The site responds to `prefers-color-scheme: dark`; the `-dark` tokens hold the dark-mode roles.

## Typography

| Family | Role | Weights | Share of text | Source |
|---|---|---|---|---|
| **SF Pro (system-ui)** (CSS: `system-ui`) | body | 400, 500, 600 | 81.0% | system (stack `system-ui, -apple-system, "system-ui", "Segoe UI", Roboto, H`, resolved on macos) |
| **Cahuenga** | display | 500 | 10.5% | webfont |
| **Spectral** | other | 400 | 7.8% | webfont |

Scale (px): 11, 13, 15, 17, 20, 24, 32. Effective ratio ≈ 1.209 (close to a minor third). Body 15px at line-height 1.4; display 32px with tracking 0em. Headings are sentence case. On a 390px viewport the body is ?px and display 13px.

## Layout

Spacing follows a 4px base unit; the most used steps are 4, 6, 8, 12, 16, 20, 24, 32px. Content sits in a fluid container. Text density 0.053 (text area / page area).

Section order (desktop). Kinds below the review threshold are shown as *section*:

1. **footer** — “Make money doing the work you believe in” (36203px, bg #FFFFFF)

## Elevation & Depth

Style: subtle. Most used shadows:

- `rgba(255, 255, 255, 0.2) 0px 1px 0px 0px inset, rgba(0, 0, 0, 0.1) 0px -1px 0px 0px inset`
- `rgba(0, 0, 0, 0.1) 0px 4px 6px -1px, rgba(0, 0, 0, 0.06) 0px 2px 4px -1px`
- `rgba(0, 0, 0, 0.05) 0px 1px 2px 0px`

## Shapes

Dominant corner radius 12px; radii in use: 4px, 8px, 12px, pill. Borders: hairline (1px).

## Components

- **button-primary**: backgroundColor `#FF6719`, textColor `#FFFFFF`, rounded `8px`, padding `0px 16px`, height `40px`, fontFamily `SF Pro (system-ui)`, fontSize `15px`, fontWeight `600`, shadow `rgba(255, 255, 255, 0.2) 0px 1px 0px 0px inset, rgba(0, 0, 0, 0.1) 0px -1px 0px 0px inset` (e.g. “Start your Substack”)
- **button-secondary**: backgroundColor `#161718`, textColor `#EEEEEE`, rounded `8px`, padding `0px 8px`, height `32px`, fontFamily `SF Pro (system-ui)`, fontSize `13px`, fontWeight `600`, shadow `rgba(255, 255, 255, 0.2) 0px 1px 0px 0px inset, rgba(0, 0, 0, 0.1) 0px -1px 0px 0px inset` (e.g. “Verify age”)
- **card**: rounded `12px`, padding `32px`, border `1px solid #0000001A`, shadow `rgba(0, 0, 0, 0.1) 0px 4px 6px -1px, rgba(0, 0, 0, 0.06) 0px 2px 4px -1px`
- **input**: rounded `12px`, height `40px`, padding `0px 40px`, backgroundColor `#FFFFFF`, border `1px solid #0000001A`

## Do's and Don'ts

- Do reserve `#FF6719` for primary actions and highlights; it covers only 0.38% of the painted page.
- Do set body copy in SF Pro (system-ui) at 15px / 1.4.
- Do use Cahuenga only for display sizes, not for body text.
- Don't introduce font weights beyond 400, 500, 600.
- Do keep corners at 12px for most controls, and use the larger radii only for cards and media.
- Do snap spacing to multiples of 4px.
- Don't copy this site's logos, illustrations, photography or copy; use the system, not the brand assets.

## Provenance

Spec v2, extractor 0.2.0. Render quality: **ok**. Vision pass: not run. Fields below confidence 0.7 are hedged or left out above: `color.accent_strategy`, `layout.columns`, `layout.hero`, `layout.section_count`, `space.section_padding_px`. Full per-field provenance is in `spec.json`.