Actual CSS

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

Actual CSS claims a documented set of global class names; the package publishes it as actual-css/reserved-classes.json.

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

Install

npm install actual-css

Import the full framework in your CSS:

@import "actual-css/full";

actual-css/full ships every functional family. The bare actual-css entrypoint is the minimal core (reset, tokens, theme, base, intents, variants, focus, print).

Or import only the pieces you use:

@import "actual-css/css";
@import "actual-css/css/layout";
@import "actual-css/css/components/button";
@import "actual-css/css/components/card";
@import "actual-css/css/forms";
@import "actual-css/css/components/flyout";
@import "actual-css/css/utilities";

actual-css/css is the minimal core. 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.

For a flattened custom bundle, import the source entrypoints you want from actual-css/css and run 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.

You can also use the compiled full bundle directly:

<link rel="stylesheet" href="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. .inverted is a shared surface modifier: it paints any block with the inverse surface. .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 typography 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; .inverted is a shared surface modifier; 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.

Patterns — actions, 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.

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, and input masks.

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

Use the full module:

<script src="actual.full.js" type="module"></script>

Or import only the enhancers you need:

import "actual-css/js/dialog";
import "actual-css/js/flyout";
import "actual-css/js/filter";
import "actual-css/js/mask";
import "actual-css/js/tooltip";

The package does not maintain separate partial bundles. Modular entrypoints map to source files, so each project can compose the framework shape it needs. To customize the full runtime, comment the imports you do not want in src/js/full.js and rebuild the JavaScript bundle. 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 Progressive Enhancements for custom filters, textarea autogrow, ajax forms, and htmx-like patterns.

Distribution

• dist/actual.css — readable core CSS.
• dist/actual.min.css — the core, minified for production.
• dist/actual.full.css — readable full-bundle CSS (every family).
• dist/actual.full.min.css — the full bundle, minified for production.

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.

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.

License

MIT

Docs

The documentation site is generated into site/ from the source pages under docs/pages/. Start at site/index.html, or build it locally with bun run build:docs.