GitHub-Dark

Installation

1. Install Stylus for Firefox, Chrome or Cascadea for Safari.
2. Install github-dark.user.css.
3. Set GitHub itself to dark mode, the style builds on GitHub's dark theme.

For GitHub Enterprise, add domain("github.example.com") to both GitHub @-moz-document rules in the installed style. Extensions that use GitHub's CSS variables, like Refined GitHub, follow the theme automatically.

Options

Change these in the style's settings, in Stylus via the gear icon next to the style.

• Base color: color of links and highlights.
• Background color: page color behind the background image.
• Background: Cross-Hatch, Uniform Tile, Random Tile, None, or Custom to use the image from Custom Background.
• Background image type: tile the image, or scale it to fit the window.
• Background image attachment: scroll the image with the page, or keep it fixed.
• GitHub syntax theme: colors code views, diffs and markdown.
• CodeMirror syntax theme: colors the file and gist editors.
• Jupyter syntax theme: colors notebook previews.
• Code Tab size: width of tabs in code, 2, 4 or 8.
• Unrounded labels and avatars: enabled by default, gives labels, counters, state badges, topics and avatars slightly rounded corners instead of pill and circle shapes.

Custom Background

Set Background to Custom and Custom Background to an image wrapped in url(), like url(https://github.com/user-attachments/assets/…), a bare URL won't work. GitHub's Content Security Policy only allows images from github.com, *.githubusercontent.com and data: URIs, so use one of these:

1. Drag the image into any GitHub comment box and copy the uploaded URL, there's no need to submit the comment.
2. Commit it to a public repository and use its raw.githubusercontent.com URL.
3. Inline a small image as a base64 data: URI.

Syntax Themes

Every theme is available for all three syntax theme options. The preview shows the GitHub syntax themes.

Styled Sites

• github.com
• gist.github.com
• support.github.com
• vscode-auth.github.com
• githubstatus.com
• Raw files on raw.githubusercontent.com and gist.githubusercontent.com
• Rendered Jupyter notebooks on notebooks.githubusercontent.com

Additional Userstyles

• GitHub Custom Fonts: code font family and size, the font must be installed locally.
• GitHub Code Wrap: wrap long code lines in diffs, gists and markdown.
• GitHub Dark Diff Color Customizer: custom diff colors, colorblind friendly by default.

Development

Edit github-dark.user.css, there is no build step. It overrides GitHub's Primer CSS variables, plus a few rules with stable selectors for things variables can't reach. Prefer a variable over a rule and never use GitHub's hashed class names.

Run make install to test it in Stylus and make lint to lint it. Release with make patch, make minor or make major, which bump the version of all styles, then commit, tag and push.