I found a solution, helped me this extantion https://github.com/ecmel/vscode-html-css.
Thanks you so much Ecmel Ercan and @tme_317 for your thoughts!
But this extension not worked with HTML (EEx) files. I contributed to this. Until the author has merged pull-request, you can use my branch: https://github.com/reducio/vscode-html-css/tree/add-html-eex
git clone https://github.com/reducio/vscode-html-css/tree/add-html-eex
# deps may be need, if you need hack this code
npm install -g typescript
npm install -g yo generator-code
npm install -g vsce
npm i -g @zeit/ncc
So, after run
vsce package you get file
vscode-html-css-0.2.3.vsix in root project folder.
Then you need install extension manually:
Don’t forget about settings of extension.
In settings.json add:
You can view a list of attributes via
ctrl + space.
Enjoy auto completion Tailwind CSS in your HTML (EEx) files.
Upvote, please: https://stackoverflow.com/questions/58013281/how-to-force-the-tailwind-css-intellisense-extension-for-vscode-work-with-html/58017659#58017659