HTML and CSS¶
Zulip CSS organization¶
The Zulip application’s CSS can be found in the
directory. Zulip uses Bootstrap as its
main third-party CSS library.
Zulip currently does not use any CSS preprocessors, and is organized
into several files. For most pages, the CSS is combined into a single
CSS file by the static asset pipeline,
controlled by the
PIPELINE_CSS code in
The CSS files are:
portico.css- Main CSS for logged-out pages
pygments.css- CSS for Python syntax highlighting
activity.css- CSS for the
fonts.css- Fonts for text in the Zulip app
static/third/thirdparty-fonts.css- Font Awesome (used for icons)
The CSS for the Zulip web application UI is primarily here:
settings.css- CSS for the Zulip settings and administration pages
zulip.css- CSS for the rest of the Zulip logged-in app
media.css- CSS for media queries (particularly related to screen width)
We are in the process of splitting zulip.css into several more files; help with that project is very welcome!
Editing Zulip CSS¶
If you aren’t experienced with doing web development and want to make CSS changes, we recommend reading the excellent Chrome web inspector guide on editing HTML/CSS, especially the section on CSS to learn about all the great tools that you can use to modify and test changes to CSS interactively in-browser (without even having the reload the page!).
CSS Style guidelines¶
Avoid duplicated code¶
Without care, it’s easy for a web application to end up with thousands of lines of duplicated CSS code, which can make it very difficult to understand the current styling or modify it. We would very much like to avoid such a fate. So please make an effort to reuse existing styling, clean up now-unused CSS, etc., to keep things maintainable.
Be consistent with existing similar UI¶
Ideally, do this by reusing existing CSS declarations, so that any improvements we make to the styling can improve all similar UI elements.
Use clear, unique names for classes and object IDs¶
This makes it much easier to read the code and use
git grep to find
where a particular class is used.
When changing any part of the Zulip CSS, it’s important to check that the new CSS looks good at a wide range of screen widths, from very wide screen (e.g. 1920px) all the way down to narrow phone screens (e.g. 480px).
For complex changes, it’s definitely worth testing in a few different browsers to make sure things look the same.