A command for checking CSS files for syntax errors, style problems, possible bugs, performance issues, accessibility concerns, and browser compatibility warnings.

Use it to lint selected CSS files or all CSS files in a project, using configurable rules and tools such as Stylelint.

It catches problems before CSS reaches users and helps keep styles consistent and maintainable.

css-lint — Command by andronics

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods

npx agentmods add commands/andronics/claude-plugin-css-pro/css-lint

Clone the repo

git clone --depth 1 https://github.com/andronics/claude-plugin-css-pro

Per session 8 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 1,877 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. Scan, not verified.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5	$0.00008	$0.01877
Opus 5	$0.00004	$0.00938
Sonnet 5	$0.00002	$0.00375
Haiku 4.5	$0.00001	$0.00188

Measured yesterday against content hash 51935dcbac0a, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

css-lint scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

commands/css-lint.md · 338 lines

How it starts

The opening of the file, as written. The whole thing — 338 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CSS Linting

I'll lint your CSS files to catch errors, enforce coding standards, and ensure best practices.

Target Files

Linting: $ARGUMENTS

If no specific files provided, I'll lint all CSS files in the project.

Linting Capabilities

What I Check

1. Syntax Errors

Invalid CSS syntax
Malformed selectors
Incorrect property values
Missing semicolons/braces
Invalid color formats

2. Best Practices

Naming conventions (BEM, camelCase, kebab-case)
Selector specificity limits
Nesting depth limits
Property order
Shorthand usage

3. Potential Bugs

Duplicate selectors
Overqualified selectors
Vendor prefix issues
Known browser bugs
!important overuse

4. Performance

Universal selectors
Expensive selectors
Large file sizes
Too many rules
Render-blocking issues

5. Accessibility

Color contrast warnings
Focus style requirements
Text sizing issues
Motion preferences

6. Compatibility

Browser support warnings
Missing vendor prefixes
Unsupported properties
Feature query suggestions

Linting Tools

Stylelint (Recommended)

I'll use Stylelint with appropriate configurations:

// .stylelintrc.js
module.exports = {
  extends: [
    'stylelint-config-standard',
    'stylelint-config-recommended'
  ],
  rules: {
    // Naming
    'selector-class-pattern': '^[a-z][a-z0-9-]*(__[a-z0-9-]+)?(--[a-z0-9-]+)?$',

    // Specificity
    'selector-max-id': 0,
    'selector-max-specificity': '0,4,0',
    'selector-max-compound-selectors': 3,

    // Best practices
    'declaration-no-important': true,
    'selector-no-qualifying-type': true,
    'shorthand-property-no-redundant-values': true,

    // Performance
    'selector-max-universal': 0,
    'selector-max-type': 2,

    // Order
    'order/properties-alphabetical-order': true,

    // Accessibility
    'a11y/media-prefers-reduced-motion': true,
    'a11y/no-outline-none': true,
  }
};

Lint Report Format

Read the full file on GitHub · 338 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

yesterday First seen · 338 lines · 8 tokens per session scan A 51935dcbac0a

Subscribe to this mod's changes

css-lint is a command published in the GitHub repository andronics/claude-plugin-css-pro (2 stars, last pushed 10mo ago), licensed MIT. It adds 8 tokens to every session and 1,877 once invoked, about $0.0000 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Code review Debugging Frontend

css-lint