If it doesn't work following the instructions just use a quick workaround for now (tailwind.config.js), why waste time? See troubleshooting at the end of plugin instructions. So for Tailwind v4:
In tailwind.config.js (create one in root of the project):
/** @type {import('tailwindcss').Config} */
export default {
content: ['./index.html', './src/**/*.{html,js}'],
theme: {
extend: {},
},
plugins: [],
}
Go to .vscode folder > settings.json and add:
"tailwindCSS.experimental.configFile": "tailwind.config.js"
Go to the Tailwind CSS intellisense plugin > settings > install specific version > 0.10.15
Restart plugin (if it stops working, just ctrl + s and type again)
It's ugly, it's definitely not the solution but it works. Just till they fix it.