⚠️   Notice: This project is not actively maintained. Reach out to @keenanpayne or @jaiheravi if you would like to chat about it ✌🏻

Concise CSS is a lightweight CSS framework and preprocessor. It gives you a solid foundation without the bloat. It has three parts, and you can use only the ones you need:

• The preprocessor: a CLI and a PostCSS plugin that compile .pcss files. They add imports, a type scale, named breakpoints and inline media queries on top of modern CSS (nesting, range queries, rlh units).
• The styles: core (base styles for HTML elements), ui (a small kit of components) and utils (helper classes).
• Precompiled CSS for projects that don't need a build step.

Documentation: concisecss.com

Installation

npm install -D concise.css

Node.js 22.22 or newer is required.

Quick start

Create a main.pcss file:

@import 'concise.css';          /* core + ui + utils */

/* Your styles */
.hero {
  margin-bottom: 2rlh;          /* two lines of the vertical rhythm (native CSS) */
  font-size: 5;                 /* step 5 of the type scale */
  padding: 1rlh ?if media (--medium);
}

Compile it:

npx concise compile main.pcss main.css

Add -w (--watch) to recompile when the file, or any file it imports, changes. To run it from package.json:

"scripts": {
  "css": "concise compile src/main.pcss dist/main.css",
  "css:watch": "concise compile src/main.pcss dist/main.css -w"
}

Using the styles

Import everything or only the parts you need:

@import 'concise.css';                          /* everything */
@import 'concise.css/core';                     /* base styles for HTML elements */
@import 'concise.css/ui';                       /* components: see ui/README.md */
@import 'concise.css/utils';                    /* helper classes: see utils/README.md */
@import 'concise.css/utils/margins-responsive'; /* opt-in responsive margin classes */
@import 'concise.css/core/settings.pcss';       /* a single file */

Every part imports the settings it needs, and each file is only included once.

Settings

All settings are custom properties and custom media queries in core/settings.pcss: colors, fonts, spacing, the type ratio and the breakpoints. Override them after importing Concise:

@import 'concise.css';

@custom-media --medium (width >= 900px);

:root {
  --color-base-primary: rebeccapurple;
  --type-ratio: 1.25;
  line-height: 1.6;
}

Colors, fonts, spacing and the type ratio are regular custom properties, so they can also change at runtime, even per component. Only the breakpoints are resolved when compiling. Vertical rhythm uses the native rlh unit, so it follows the line-height of :root.

The .pcss syntax

.pcss files are CSS with a few additions. Any valid CSS is valid .pcss, and native features such as nesting, media query ranges and the rlh unit are left as written.

Feature	Write	Get
Imports	@import 'partials/header';	Inlines partials/header.pcss, _header.pcss, header.css or header/index.pcss. Bare names are looked up next to the file first, then in node_modules
Type scale	font-size: 4	calc(pow(var(--type-ratio), 2) * 1rem): step 2 is 1rem, and each step multiplies by --type-ratio
Named breakpoints	@media (--medium) {}	@media (width >= 768px) {}
Inline queries	padding: 0 ?if media (--small);	A @media block placed right after the rule
Query blocks	.a { ?if media (--small) { … } }	Same, for several declarations

Breakpoints defined in the settings: --extra-small, --small, --medium, --large, --extra-large, --only-small, --only-medium and --only-large.

Precompiled CSS

Every release ships compiled stylesheets in dist/: concise.css, core.css, ui.css and utils.css, each with a .min.css version. They can be used from a CDN:

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/concise.css@5/dist/concise.min.css">

Using the PostCSS plugin

Concise is also a PostCSS plugin, so it works with any tool that runs PostCSS:

// postcss.config.js
import concise from 'concise.css'

export default { plugins: [concise()] }

// postcss.config.cjs
module.exports = { plugins: [require('concise.css')()] }

Options, all optional:

concise({
  import: { /* postcss-import options */ }
})

Browser support

The compiled CSS targets current browsers and uses native nesting, media query range syntax, the rlh unit, pow() and, in the UI kit, relative color syntax. No vendor prefixes are added. To support older browsers, add plugins such as postcss-nested, postcss-media-minmax or autoprefixer after concise() in your own PostCSS config.

Upgrading from v4

• Sass → .pcss: rename your .scss files to .pcss, then replace Sass features:
  • getColor(base, primary) → var(--color-base-primary)
  • $spacing-m → var(--spacing-m)
  • typeScale(3) → font-size: 3
  • // comments → /* comments */
  • loops and mixins → plain CSS
  • &-suffix / &_suffix selector concatenation → full class names (native nesting can't build selectors from parts)
• lh unit → rlh: Concise's lh unit was the root line height, which is native rlh. Replace 1.5lh with 1.5rlh. Native lh is the element's own line height.
• Removed options: lh, typeScale and autoprefixer. Add Autoprefixer to your own PostCSS config if you need it.
• One package: concise-ui, concise-utils and @concisecss/core are now part of concise.css. Import concise.css/ui, concise.css/utils and concise.css/core instead.
• The grid from v4 core is not part of v5. Use CSS grid or flexbox.
• Responsive margins are no longer controlled by $responsive-margins. Import concise.css/utils/margins-responsive instead.

Development

npm install
npm test               # fixtures, plugin, CLI and stylesheet snapshot tests
npm run test:update    # accept stylesheet changes after reviewing the snapshot diff
npm run build          # write dist/

To check the styles visually, run npm run build and open playground/core.html or playground/ui.html.

See CONTRIBUTING.md for how to contribute.

Changelog

You can keep up to date with the changes on our releases page.

License

Code released under the MIT license. Documentation released under Creative Commons.