# Tailwind CSS v4.3.0 — Release & Upgrade Intelligence
- **Product:** Tailwind CSS (https://tailwindcss.com)
- **Version:** v4.3.0
- **Released:** May 08, 2026
- **Impact Score:** 5/10
- **Breaking Changes:** Not verified
- **Canonical Analysis:** https://changelogs.us/tailwind/updates/v4.3.0/

## Executive Summary (TL;DR)
Tailwind CSS v4.3.0. Source highlight: Add `@container-size` utility (#18901)

## New Features
- Add `@container-size` utility (#18901)
- Add `scrollbar-{auto,thin,none}` utilities for `scrollbar-width`, and `scrollbar-thumb-*` / `scrollbar-track-*` color utilities for `scrollbar-color` (#19981, #20019)
- Add `scrollbar-gutter-*` utilities (#20018)
- Add `zoom-*` utilities (#20020)
- Add `tab-*` utilities (#20022)
- Allow using `@variant` with stacked variants (e.g. `@variant hover:focus { … }`) (#19996)

## Bug Fixes
- Ensure `@plugin` resolves package JavaScript entries instead of browser CSS entries when using `@tailwindcss/vite` (#19949)
- Fix relative `@import` and `@plugin` paths resolving from the wrong directory when using `@tailwindcss/vite` (#19965)
- Ensure CSS files containing `@variant` are processed by `@tailwindcss/vite` (#19966)
- Resolve imports relative to `base` when `result.opts.from` is not provided when using `@tailwindcss/postcss` (#19980)
- Canonicalization: preserve significant `_` whitespace in arbitrary values (#19986)
- Canonicalization: add parentheses when removing whitespace from arbitrary values would hurt readability (e.g. `w-[calc(100%---spacing(60))]` → `w-[calc(100%-(--spacing(60)))]`) (#19986)

## Upgrade Command
```bash
npm install --save-exact tailwindcss@4.3.0
```