agentmods.dev

tailwindcss

A set of rules for using Tailwind CSS version 4, a CSS framework for styling web pages. It explains the newer CSS-first setup and the package and import changes from older Tailwind versions.

In plain words
What is it for?
Use it when writing Tailwind CSS 4 styles, configuring theme variables, importing Tailwind, choosing the correct PostCSS, CLI, or Vite package, and handling older configuration files.
Why use it?
It helps avoid configuration and package mistakes when setting up or editing Tailwind CSS 4 projects.

Cursor rule for Cursor

227 5mo ago A scan 0 tokens original MIT
View the source file davis7dotsh/river
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 rules/davis7dotsh/river/tailwindcss
Clone the repo
git clone --depth 1 https://github.com/davis7dotsh/river

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 1,890 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.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.01890
Opus 5 $0.00000 $0.00945
Sonnet 5 $0.00000 $0.00378
Haiku 4.5 $0.00000 $0.00189

Measured yesterday against content hash 6c66090f4dac, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

tailwindcss 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.

Origin

Copies of this mod

4 near-identical copies found in the catalogue:

.cursor/rules/tailwindcss.mdc · 171 lines

How it starts

The opening of the file, as written. The whole thing — 171 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Tailwind CSS v4

Core Changes

  • CSS-first configuration: Configuration is now done in CSS instead of JavaScript

    • Use @theme directive in CSS instead of tailwind.config.js

    • Example:

      @import 'tailwindcss';

@theme {
	--font-display: 'Satoshi', 'sans-serif';
	--breakpoint-3xl: 1920px;
	--color-avocado-500: oklch(0.84 0.18 117.33);
	--ease-fluid: cubic-bezier(0.3, 0, 0, 1);
}

  • Legacy tailwind.config.js files can still be imported using the @config directive:

    @import 'tailwindcss';
@config "../../tailwind.config.js";

  • CSS import syntax: Use @import "tailwindcss" instead of @tailwind directives

    • Old: @tailwind base; @tailwind components; @tailwind utilities;
    • New: @import "tailwindcss";

  • Package changes:

    • PostCSS plugin is now @tailwindcss/postcss (not tailwindcss)
    • CLI is now @tailwindcss/cli
    • Vite plugin is @tailwindcss/vite
    • No need for postcss-import or autoprefixer anymore

  • Native CSS cascade layers: Uses real CSS @layer instead of Tailwind's custom implementation

Theme Configuration

  • CSS theme variables: All design tokens are available as CSS variables
    • Namespace format: --category-name (e.g., --color-blue-500, --font-sans)
    • Access in CSS: var(--color-blue-500)
    • Available namespaces:
      • --color-* : Color utilities like bg-red-500 and text-sky-300
      • --font-* : Font family utilities like font-sans
      • --text-* : Font size utilities like text-xl
      • --font-weight-* : Font weight utilities like font-bold
      • --tracking-* : Letter spacing utilities like tracking-wide
      • --leading-* : Line height utilities like leading-tight
      • --breakpoint-* : Responsive breakpoint variants like sm:*
      • --container-* : Container query variants like @sm:* and size utilities like max-w-md
      • --spacing-* : Spacing and sizing utilities like px-4 and max-h-16
      • --radius-* : Border radius utilities like rounded-sm
      • --shadow-* : Box shadow utilities like shadow-md
      • --inset-shadow-* : Inset box shadow utilities like inset-shadow-xs
      • --drop-shadow-* : Drop shadow filter utilities like drop-shadow-md
      • --blur-* : Blur filter utilities like blur-md
      • --perspective-* : Perspective utilities like perspective-near
      • --aspect-* : Aspect ratio utilities like aspect-video
      • --ease-* : Transition timing function utilities like ease-out
      • --animate-* : Animation utilities like animate-spin

Read the full file on GitHub · 171 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.

  1. yesterday First seen · 171 lines · 1,890 tokens per session scan A 6c66090f4dac

Subscribe to this mod's changes

tailwindcss is a cursor rule published in the GitHub repository davis7dotsh/river (227 stars, last pushed 5mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,890 tokens. 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 2026-08-30.

FrontendLanguagesReActWriting and docsaistreamingsveltesveltekittypescript
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