TailwindCSS v4 is now in beta: https://tailwindcss.com/docs/v4-beta

I have tested it and it works pretty great with the current version of Hugo.

Some notes and possible enhancements:

• @config seems to resolve from the root, so @config "tailwind.config.js" works fine in the common cases, but we may want to make that configurable from the Hugo side.
• I suspect the number one reason to have a config file is to set content sources (e.g. hugo_stats.json); these can also be set in the CSS with the @source; we may consider a way to control this from the Hugo side ...