# Tailwind CSS v4.1.8 — Release & Upgrade Intelligence
- **Product:** Tailwind CSS (https://tailwindcss.com)
- **Version:** v4.1.8
- **Released:** May 28, 2025
- **Impact Score:** 5/10
- **Breaking Changes:** Not verified
- **Canonical Analysis:** https://changelogs.us/tailwind/updates/v4.1.8/

## Executive Summary (TL;DR)
Tailwind CSS v4.1.8. Source highlight: Improve error messages when `@apply` fails (#18059)

## New Features
- Improve error messages when `@apply` fails (#18059)

## Bug Fixes
- Upgrade: Do not migrate declarations that look like candidates in `<style>` blocks (#18057, 18068)
- Upgrade: Don't error when looking for `tailwindcss` in pnpm monorepos (#18065)
- Upgrade: Don't error when updating dependencies in pnpm monorepos (#18065)
- Upgrade: Migrate deprecated `order-none` to `order-0` (#18126)
- Support Leptos `class:` attributes when extracting classes (#18093)
- Fix "Cannot read properties of undefined" crash on malformed arbitrary value (#18133)

## Upgrade Command
```bash
npm install --save-exact tailwindcss@4.1.8
```