Package Exports

@readium/css
@readium/css/css/ReadiumCSS-config.css
@readium/css/css/vars/fontStacks.json

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Readme

Readium CSS

A set of reference stylesheets for EPUB Reading Systems.

Readium CSS provides styles for reflowable text:

paged and scrolled views;
a “patch” for HTML5 Suggested Rendering specific to publications (e.g. extra styles for hyphenation, breaks, etc.);
default styles for unstyled ebooks;
theming;
user settings;
a set of baselines and recommendations for accessibility, overrides, and internationalization.

License

BSD-3-Clause (http://opensource.org/licenses/BSD-3-Clause)

See license.txt.

Scope of this project

The primary goal of Readium CSS is to provide Reading System implementers with reliable and modern styles for reflowable EPUB 2 and EPUB 3 files. In addition, it should provide good interoperability in the existing ecosystem, while not overriding authors’ styles unless strictly necessary.

Readium CSS stylesheets were not designed and should not be used for fixed-layout EPUB, nor other file formats like FB2, PRC, Mobi, TEI, etc.

Some issues, which may be raised during development, will be documented so that they can serve as a reference for revisions of the EPUB specification, and even future specifications.

Implementations

Readium CSS is implemented in the Readium Mobile and Readium Web projects.

You will find it in:

External use include:

Development

Active development is pulled in branch develop.

Init

Building and testing are relying on npm packages and scripts. To initialize your clone/fork, first install dev dependencies:

npm install

In case you’re encountering an error with Puppeteer, make sure you’re using at least Node v.20.11.1 – it might work with an earlier version but only the latest LTS as of March 21, 2024 has been tested.

Then create reference bitmaps for visual regression testing:

npm run test:ref

Build

To transpile all stylesheets using PostCSS:

npm run build

To test the updated styles and catch visual regression bugs:

npm run test

To update reference bitmaps after a bugfix:

npm run test:approve

Docs

Documentation can be accessed in docs.

You can alternatively download it as an EPUB file.