Actual CSS

Plain CSS component framework for new projects. Semantic classes, shared variants, small tokens, theme hooks, and progressive enhancement.

Documentation: https://lekoala.github.io/actual-css/site/

Actual CSS claims a documented set of global class names; the package publishes it as actual-css/reserved-classes.json. Tools can also read actual-css/components.json (components, imports, hooks, docs URLs) and actual-css/tokens.json (public global tokens).

For existing projects: use cascade layers, import order, or your own build-time prefix transform.

Install

npm install actual-css

Import what you use

Copy the package's src/css/actual.full.css into your project as your entry, rewrite its relative imports to package paths, and delete what you do not need — see Start from the full entry:

@import "actual-css/css";                   /* core */
@import "actual-css/css/layout";
@import "actual-css/css/forms/all";
@import "actual-css/css/components/button";
@import "actual-css/css/components/card";
@import "actual-css/css/utilities";

actual-css/css is the core (reset, tokens, theme, base, intents, variants, focus, print). Family manifests (css/layout, css/components, css/typography, css/effects, css/utilities) and their modules map one-to-one to src/css/; css/forms is the exception — it points at the native-controls base, with css/forms/all exposing the complete Forms family. See the modular import guide for the full map.

Flatten the composition for production with npx actual-css bundle src/app.css --out public/app.css --minify. The CLI resolves package subpaths and relative files, then inlines them without transpiling modern CSS.

Hand your theme to designers with bunx --bun actual-css design --theme theme.css --out design/: Figma and Penpot tokens, plus a Penpot plugin that builds the core components. See Design tools.

Full bundle (zero-config)

The bare actual-css entrypoint and actual-css/full both resolve to the complete compiled framework — useful for prototypes, CDN usage, or when bundle size is not worth optimizing:

@import "actual-css/full";

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/actual.full.min.css">

Usage

Add classes to your HTML. Components define the structure, variants change the style, and intents set the color.

<button class="btn">Click me</button>
<button class="btn primary">Save</button>
<button class="btn primary outline lg">Publish</button>
<button class="btn success soft sm">Confirm</button>

Intents such as .primary, .secondary, .success, .warning, and .danger work across components.

Variants such as .solid, .soft, .outline, and .surface are shared by components like buttons, badges, alerts, and cards. A dark or light section is a data-theme island. .ghost and .link are button-only variants.

Size variants .sm and .lg scale typography and participating component geometry consistently. Density contexts .compact and .spacious change spacing and geometry without changing font size, font width or icons.

Public Class Grammar

Actual CSS uses a small unprefixed class grammar:

.component [intent] [variant] [size] [modifier]

Components, layout helpers, form helpers, and utilities claim their documented class names. Intents are .primary, .secondary, .success, .warning, and .danger; shared variants are .solid, .soft, .outline, and .surface; button-only variants are .ghost and .link; shared sizes are .sm and .lg; density contexts are .compact and .spacious.

Undocumented is-* classes are runtime internals.

What's included

Components — button, card, badge, alert, table, accordion, breadcrumb, pagination, skeleton, spinner, avatar, key, meter, progress, joined controls, and busy indicators.

UI components — dialog, drawer, flyout, tooltip, tabs, scrollspy, context menus, and other components that rely on JavaScript or modern platform behavior.

Effects — aura, shimmer, mark sweep, and reveal: purely visual enrichment, with motion that respects reduced-motion.

Patterns — navbar and overline. These are regular source files and can be imported only when needed.

Layout primitives — .stack, .cluster, .grid, .switcher, .center, .media, .frame, .app-shell, .sidebar-layout, and .container-query.

Forms — field layout, choices, switches, selects, custom selects, control base styles, validation states, and form actions.

Prose — opt-in rich text styling with .prose.

Utilities — spacing, gaps, logical margins, truncation, muted text, circles, screen-reader-only text, text wrapping, and link variants.

Theme hooks — public tokens for color, radius, shadow, motion, and typography. Reference presets in src/css/themes/ are demo material, not default CSS or public package entrypoints.

Blocks — copy-paste marketing sections, application screens and navigation built with Actual CSS live in a separate gallery: Actual Blocks.

Modular CSS

The family manifests are the module catalog: core, layout, typography, forms, components, effects, and utilities under src/css/, each with an index.css manifest and per-module files. Import a manifest to get the family, or a single file for one module. See the modular import guide for the full map of module names to import paths.

JavaScript enhancers

Some components can be enhanced with JavaScript: dialog/drawer, flyout, tooltip, tabs, scrollspy, context menu, floating UI, opt-in data-filter input filtering, input masks, and the one-shot in-view trigger behind .reveal and .mark-sweep.

Presentation (class) and behaviour (data-enhance) are separate layers — import any primitive independently to build custom widgets. See enhancement contract and widget primitives.

Two ways to load it — pick one, never both, since each copy owns its own registries:

• Full runtime, zero-config — every built-in enhancer, compiled:

  <script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/actual.full.js" type="module"></script>

• Your own build — copy the package's src/js/full.js as your entry, rewrite its imports to package paths, keep the enhancers you need, and bundle it with your app:

  import "actual-css/js";          // enhancement-manifest loader (optional)
  import "actual-css/js/dialog";
  import "actual-css/js/flyout";
  import "actual-css/js/tooltip";

Modular entrypoints map to source files and import @lekoala/floating as a bare specifier, so they need a bundler or an import map. JavaScript modules are safe to import during server-side rendering; outside a browser, registration is a no-op.

For project-specific behavior, use actual-css/js/enhance and the small input helpers rather than patching built-in modules. See the progressive enhancement guide for custom filters, textarea autogrow, ajax forms, and htmx-like patterns.

Distribution

• dist/actual.full.css — readable full-bundle CSS (every family).
• dist/actual.full.min.css — the full bundle, minified (actual-css, actual-css/full).
• dist/actual.full.js — the complete runtime, every built-in enhancer registered.

Only the full framework is compiled. To compose, import the sources: actual-css/css/* for CSS, actual-css/js/* for JavaScript.

Modern syntax such as light-dark(), color-mix(), @container, :has(), 100dvh, and 100vi is preserved in the distributed files.

Actual CSS does not currently ship a separate compatibility build. It is designed as progressive enhancement: modern features are guarded with @supports where needed, while older browsers still receive the core styles and the layout, forms, and components.

For more conservative fallbacks, import and compose the source entrypoints directly.

Versioning

Actual CSS is before 1.0:

• A minor release (0.12 → 0.13) may remove or rename classes and hooks. Each one adds a section to Upgrading.
• A patch release (0.12.0 → 0.12.1) keeps every class and hook. It fixes bugs and may add hooks, so a fix can still move a rendering by a few pixels.

The floating [email protected] CDN path takes patches automatically. Pin the exact version ([email protected]) when the rendering must not change without a review.

Browser support

Actual CSS is built around progressive enhancement.

| Tier | Firefox | Safari | Chromium | | ----------- | -------: | ------: | -------: | | Degraded | 78+ | 14+ | 88+ | | Minimal | 125+ | 17+ | 116+ | | Recommended | 129+ | 17.5+ | 123+ |

Degraded — semantic HTML and core CSS remain usable. JavaScript enhancements are outside the supported contract.

Minimal — full Actual support, including the JavaScript runtime. The runtime assumes modern browser APIs — including the native manual Popover transport used by interactive surfaces — and does not ship legacy compatibility layers or polyfills.

Degraded browsers may execute some enhancements successfully, but this behavior is not tested or preserved.

Cascade layers

Actual CSS is layer-compatible, not layer-dependent. The default actual.css file is unlayered. See docs/design-notes/cascade-layer.md for details.

AI Disclosure

Actual CSS uses AI-assisted tooling for code generation, refactoring, and debugging. Patterns and architecture come from hand-written prototypes and iterative human-driven refinement. AI output is reviewed, tested, and owned by the maintainer.

Coding agents

Actual CSS ships a starter agent skill under skills/actual-css/.

It teaches coding agents how to use the framework's vocabulary, public hooks, layout primitives and progressive enhancements without recreating framework behavior in application CSS.

Copy it into your project's agent skills and extend it with your application's theme, loaded modules and local conventions. Visual direction belongs in your own DESIGN.md; see Coding agents and DESIGN.md.

License

MIT

Docs

The documentation site is published at https://lekoala.github.io/actual-css/site/. It is generated from the source pages under docs/pages/; in a clone, run bun run build:all (or build:dist, build:js and build:docs) and open site/index.html.