# CodeMirror design system

> CodeMirror design system measured from codemirror.net: Merriweather font, #066ADF primary, 8 color hex codes, type scale, spacing and a free DESIGN.md.

Canonical page: https://sitepeel.dev/design-md/codemirror.net/

CodeMirror’s website (codemirror.net) uses the Merriweather font and #066ADF as its main color on a white background. Measured by Sitepeel on November 4, 2026.

## What font does CodeMirror use?

CodeMirror uses Merriweather (weight 700) and Source Sans Pro (weights 400 and 600), with SFMono-Regular for code on codemirror.net. Page titles are 32px at weight 700 (22px on phones) and body text is 16px. Measured on November 4, 2026.

- Merriweather (weights 700)
- Source Sans Pro (weights 400, 600)
- SFMono-Regular (weights 400)

## CodeMirror colors: palette and hex codes

CodeMirror’s main colors are #FFFFFF (white) for the background, #000000 (near black) for text and #066ADF (vivid blue) as the main accent, with #0000FF (vivid indigo) and #EE4400 (vivid orange) as other accents. Measured on November 4, 2026.

- #FFFFFF: white
- #000000: near black
- #777777: slate
- #E5E5E5: mist
- #066ADF: vivid blue
- #0000FF: vivid indigo
- #EE4400: vivid orange

## What is CodeMirror built with?

CodeMirror’s website (codemirror.net) is built with Nginx. Measured on November 4, 2026.

- Server: Nginx 1.26.3

## Questions and answers

### What font does CodeMirror use?

CodeMirror’s website uses Merriweather (weight 700) and Source Sans Pro (weights 400 and 600), with SFMono-Regular for code. Page titles are 32px at weight 700 (22px on phones) and body text is 16px. Measured on November 4, 2026.

### What are the CodeMirror colors and hex codes?

On codemirror.net: #FFFFFF (white) for the background, #000000 (near black) for text and #066ADF (vivid blue) as the main accent, with #0000FF (vivid indigo) and #EE4400 (vivid orange) as other accents. The color palette above lists all 8 colors with their hex codes and where each one is used.

### What is the CodeMirror design system?

The design system on this page is codemirror.net’s, as measured on November 4, 2026: Merriweather type, #066ADF as the main color and square corners, written down as a DESIGN.md. It is not CodeMirror’s own documentation.

### What is CodeMirror built with?

CodeMirror’s website (codemirror.net) is built with Nginx. Measured on November 4, 2026.

### What is the CodeMirror DESIGN.md?

A plain-text file with CodeMirror’s measured colors, type, spacing, corners and components as tokens, plus short rules, in the DESIGN.md format Google published with Stitch. Your AI coding agent reads it and builds in this style. More about DESIGN.md.

### How do I use it with Claude Code or Cursor?

Download the file and put it in your project’s root folder, then ask your agent to follow DESIGN.md. Step-by-step guides: Claude Code, Cursor, Codex, GitHub Copilot.

### Is this CodeMirror’s official design system?

No. Sitepeel measured it from codemirror.net’s public page on November 4, 2026. It is an independent analysis, not made or approved by CodeMirror.

### Can I use CodeMirror’s style in my own product?

Use it to learn, prototype and compare. For a real product, make the style your own, and never copy CodeMirror’s logo, name, pictures or text.

### How accurate are the values?

Each value was measured on the rendered page after it fully loaded, on desktop and mobile: colors where they appear, type with tracking, spacing, corners, shadows and hover states. Sites change, so check the date at the top.

## Files

- [DESIGN.md](https://sitepeel.dev/design-md/codemirror.net/DESIGN.md): the plain file to put in your project.
- [All brand DESIGN.md files](https://sitepeel.dev/design-md/examples/index.md)

Independent analysis by Sitepeel (sitepeel.dev), not affiliated with CodeMirror.

## The DESIGN.md file

```markdown
---
version: alpha
name: CodeMirror
description: "Light interface measured from codemirror.net: Merriweather type with Source Sans Pro, vivid blue accents, flat surfaces and square corners."
colors:
  background: "#FFFFFF"
  surface: "#FFFFFF"
  on-surface: "#000000"
  on-background: "#000000"
  on-surface-variant: "#777777"
  outline: "#E5E5E5"
  primary: "#066ADF"
  on-primary: "#FFFFFF"
  secondary: "#0000FF"
  tertiary: "#EE4400"
typography:
  headline-display:
    fontFamily: Merriweather
    fontSize: 32px
    fontWeight: 700
    lineHeight: 1.25
  body-md:
    fontFamily: Source Sans Pro
    fontSize: 16px
    fontWeight: 400
    lineHeight: 1.45
  label-lg:
    fontFamily: Merriweather
    fontSize: 16px
    fontWeight: 700
    lineHeight: 1.63
  label-md:
    fontFamily: Source Sans Pro
    fontSize: 14px
    fontWeight: 600
    lineHeight: 1.45
  label-sm:
    fontFamily: Merriweather
    fontSize: 12px
    fontWeight: 700
  code:
    fontFamily: SFMono-Regular
    fontSize: 14px
    fontWeight: 400
    lineHeight: 1.4
  headline-display-mobile:
    fontFamily: Merriweather
    fontSize: 22px
    fontWeight: 700
    lineHeight: 1.82
rounded:
  none: 0px
spacing:
  xs: 3px
  sm: 8px
  md: 12px
  lg: 17px
  xl: 50px
  gutter: 17px
  section: 62px
  container: 720px
components:
  link:
    textColor: "{colors.on-surface}"
---

# CodeMirror Design System

## Overview

The interface is light, built on **White (#FFFFFF)** with **Near Black (#000000)** text, and **Vivid Blue (#066ADF)** as the main accent.

Type is set in **Merriweather** and **Source Sans Pro**, with **SFMono-Regular** for code. Headlines run large; body text is 16px. The surface language is flat. Corners are square.

Measured from [codemirror.net](https://codemirror.net/) on November 4, 2026 at 1440×900 and 390×844 from 190 rendered elements. Values are computed styles from the live page, not the original source files.

## Colors

The palette has 8 roles.

- **White (#FFFFFF):** Page background, seen 1 time. Token `background`.
- **Near Black (#000000):** Primary text and headings, seen 67 times. Token `on-surface`.
- **Slate (#777777):** Secondary text, seen 3 times. Token `on-surface-variant`.
- **Mist (#E5E5E5):** Borders and dividers, seen 4 times. Token `outline`.
- **Vivid Blue (#066ADF):** Most used accent color, seen 9 times. Token `primary`.
- **White (#FFFFFF):** Text and icons on primary. Token `on-primary`.
- **Vivid Indigo (#0000FF):** Accent in text, fills and borders, seen 2 times. Token `secondary`.
- **Vivid Orange (#EE4400):** Accent in text, fills and borders, seen 2 times. Token `tertiary`.

## Typography

**Merriweather**, **Source Sans Pro** and **SFMono-Regular** (monospace) share the interface. Fallback stack: `Merriweather`.

- **headline-display:** Merriweather 32px at weight 700, line height 1.25 (22px on mobile). Page title (h1).
- **body-md:** Source Sans Pro 16px at weight 400, line height 1.45. Body text.
- **label-lg:** Merriweather 16px at weight 700, line height 1.63. Large buttons and tabs.
- **label-md:** Source Sans Pro 14px at weight 600, line height 1.45. Buttons, navigation and labels.
- **label-sm:** Merriweather 12px at weight 700. Small labels and badges.
- **code:** SFMono-Regular 14px at weight 400, line height 1.4. Code and technical values.

## Layout

Spacing does not follow a strict grid: 50% of measured values are multiples of 4px, so match the measured steps rather than rounding to a grid.

- **Scale:** xs 3px, sm 8px, md 12px, lg 17px, xl 50px.
- **Sections:** 62px vertical padding between major sections.
- **Gaps:** 17px is the most common gap in flex and grid layouts.
- **Container:** content is capped at 720px.
- **Breakpoints:** 830px, 1130px.

## Elevation & Depth

The design is flat: no shadows were measured. Hierarchy comes from color contrast and #E5E5E5 borders.

## Shapes

Corners are square. Measured radii, most used first:

- **none (0px):** measured.

## Components

Measured from the rendered page. Token values reference the tokens above.

- **link:** transparent fill, #000000 text, padding 0px.

## Do's and Don'ts

- Do use #FFFFFF for the page.
- Do keep text in 2 levels: #000000, #777777.
- Do reserve #066ADF for primary actions and key highlights.
- Do reuse the measured spacing steps (8px, 12px, 17px).
- Don't use #777777 for body text; it reaches 4.48:1 on #FFFFFF. Keep it for large text or metadata.
- Don't add drop shadows for depth; use borders and contrast.
- Don't introduce new font families beyond Merriweather, Source Sans Pro and SFMono-Regular.
- Don't use #066ADF for large backgrounds or body text.

Generated by [Sitepeel](https://sitepeel.dev/design-md/codemirror.net/), the free DESIGN.md generator (engine 2026.10.29+b828a475ee10).

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