Minium CSS

The minimum CSS and HTML to build anything.

Minium is a semantic-first CSS library that makes ordinary HTML look good, then adds class-light layouts and components for building real interfaces.

See what it looks like | Read the documentation

Why Minium?

Writing semantic HTML should get you further than an unstyled page.

With Minium, elements such as headings, links, tables, forms, buttons, details, and dialog work as the baseline. When the interface needs more structure, one meaningful class can add a layout or component. Utilities are there to adjust the result, not construct it one declaration at a time.

<main class="container flow">
  <h1>Latest articles</h1>

  <section class="grid thirds">
    <article class="card">
      <h2>Write the HTML you mean</h2>
      <p>Semantic elements provide the foundation. Minium does the styling.</p>
      <a href="/articles/semantic-html" role="button">Read article</a>
    </article>
  </section>
</main>

The library takes on more CSS when it lets users write meaningfully less HTML. Features that do not pay back their bundle cost through real use do not belong.

Quick start

Use the CDN

Load the minified stylesheet from jsDelivr without installing anything:

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

To add a color theme, load its stylesheet after the core stylesheet:

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/@troennes/[email protected]/dist/themes/blue.css">

Install with npm

npm install @troennes/minium

Import the core stylesheet from your application's entry point:

import "@troennes/minium";

To use the minified build explicitly, import its package subpath:

import "@troennes/minium/min";

If your tools cannot import CSS from a package, copy the complete node_modules/@troennes/minium/dist/ directory into your project's public assets. Then link the copied stylesheet:

<link rel="stylesheet" href="/styles/minium.min.css">

Keep the included fonts/ directory beside the stylesheet so its relative font URLs continue to work.

Build from source

Choose this option if you want to modify Minium's source CSS before using it. Building requires Node.js 22 or later.

1. Download the latest source ZIP from GitHub.

2. Extract the ZIP and open a terminal in the extracted minium-main directory.

3. Install the build dependencies and build Minium:

   npm install
   npm run build
   

4. Copy the complete dist/ directory into your project's public assets.

5. Link the copied stylesheet from your HTML:

   <link rel="stylesheet" href="/styles/minium/minium.min.css">
   

Keep the generated fonts/ directory beside the stylesheet so its relative font URLs continue to work.

Start with semantic HTML

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Hello, world</title>
  <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/@troennes/[email protected]/dist/minium.min.css">
</head>
<body>
  <main class="container flow">
    <h1>Hello, world</h1>
    <p>Your HTML already has a design system.</p>
    <button>Continue</button>
  </main>
</body>
</html>

Explore the quick-start documentation when you are ready to add layouts and components.

Customize the theme

Minium includes 31 color themes. Load one after the core stylesheet:

<link rel="stylesheet" href="minium.min.css">
<link rel="stylesheet" href="themes/blue.css">

Custom properties control colors, type, spacing, radii, shadows, and component density. Override them in @layer theme without specificity tricks. See the customization guide for details.

Features

• Semantic HTML first. Common document, typography, table, form, and interactive elements look good without classes
• Composable layout primitives. Use .container, .flow, .cluster, .grid, .sidebar, .switcher, .repel, and .frame to express common compositions with one class
• Common components. Minium includes cards, alerts, modals, dropdowns, accordions, navigation, tabs, pagination, badges, avatars, skeletons, loading and progress states, and tooltips
• Class-light by design. Components own their structure and appearance, so meaningful classes replace wrapper stacks and utility chains
• Accessible defaults. Minium favors native elements and browser behavior, preserves visible focus states, styles semantic and ARIA states, and respects reduced-motion preferences
• Customization. Custom properties control color, type, spacing, radii, shadows, and density
• Pure modern CSS. There is no Sass, preprocessor, build-time configuration, or JavaScript dependency
• MIT licensed. Use Minium in personal, commercial, and open-source projects
• RTL support. Logical properties and targeted RTL rules let layouts and components follow the document direction
• 31 color themes. One theme per Radix Color scale, each a 1.3–2.7 KB gzipped stylesheet with light and dark values and Display P3 colors for capable displays. Load one file to switch themes, with no build step
• Light and dark modes. Theme colors follow the system preference by default and can be explicitly set to light or dark
• Responsive layouts. Fluid type and spacing, intrinsic layouts, wrapping, and constrained components adapt to available space without a large breakpoint system
• Small fixed bundle. The current minified core is ~14.3 KiB gzipped, so its cost is predictable before you write any HTML
• Token-bounded utilities. Adjust spacing, gaps, radii, surfaces, and other common values without opening an unlimited utility API or reaching for inline styles
• Cascade layers. Library styles remain predictable, and project overrides stay straightforward
• Opt-in integrations. CSS for third-party markup ships separately from the core library
• AI-readable reference. documents Minium's API and usage constraints in one place (~11k tokens)

Documentation

• Quick start
• Layouts
• Components
• Forms
• Utilities
• Customization
• Integrations
• Color palette
• Complete AI-readable reference

The dashboard example uses semantic HTML and Minium classes to build an application shell.

Background

I built Minium because I was tired of bloated CSS frameworks, extra dependencies, and constant churn. I wanted modern CSS that makes semantic HTML look good, avoids short-lived design trends, and needs little maintenance.

I have worked on Minium on and off since 2022 and rebuilt it from scratch three times as its fundamental ideas evolved. Pico remains the main inspiration, alongside CUBE CSS and Every Layout.

After three rebuilds, Minium’s core ideas feel settled. It works well for the sites and interfaces I build. Broader use will help reveal what still needs work before version 1.0.

Project status: 0.x

The library is ready to use, but it has not yet been tested across a wide range of websites, applications, and browsers. Expect breaking changes in minor releases before 1.0. The changelog lists each change and the steps to upgrade.

Please open an issue if you find rendering or accessibility problems, unclear documentation, awkward component boundaries, or APIs that require unnecessary HTML. Include a small reproduction and browser details when relevant.

Browser support

Minium targets the current stable releases of Chrome, Firefox, and Safari. Other Chromium-based browsers (such as Edge) should also work, but are not tested directly.

Development

Development requires Node.js 22 or later.

npm install
npm test              # lint + theme check + gzip size budget
npm run build         # build core CSS, minified CSS, fonts and themes
npm run build:themes  # regenerate color roles and themes from scripts/themes.json

License

Minium is available under the MIT License.

About the name

Minium is the historical name for red lead, an orange-red pigment. An unrelated CSS project also used the same name in 2018; this is a separate project.