v4.1.17 Cannot apply py-0.5

[nam-co]

Latest release: v4.1.17 (CLI standalone executable)

Im suddenly getting errors on simple stuff like:
Error: Cannot apply unknown utility class py-0.5 or Cannot apply unknown utility class md:px-2

Call;
tailwindcss -i ./resources/css/frontend.css -o ./public/assets/css/frontend.css

Hope somebody can help me, @apply is such a great feature

Thanks

[wongjn]

Consider providing a git repo that reproduces the issue and we can take a look for you.

---

As an aside, Adam Wathan (creator of Tailwind) does seem to advocate avoiding @apply:

• https://twitter.com/adamwathan/status/1226511611592085504
• https://twitter.com/adamwathan/status/1559250403547652097
• https://x.com/adamwathan/status/1890406016291938701

[nam-co]

I've seen he doesn't like it, but users do, @apply is definitely easy and magical, anyway it was actually another error, a non css (html) on the file was making tailwind show this error, strange, thanks

[rozsazoltan]

This isn't about dislike. If you reference py-5 in multiple places when using CSS modules, then each CSS module will repeat the value of py-5 completely unnecessarily. You bloat the CSS, and in the end, once everything is added up, the visitor downloads much more CSS code by the time all your CSS files load than if a single global CSS file had been downloaded the first time.

On top of that, with JS frameworks it's child's play to create reusable components, so for example creating a .btn class with @apply quickly becomes unnecessary, because you can simply make a Button component with inline class definitions and reuse the Button component endlessly.

I think using @apply in a global file isn't as problematic as with CSS modules.

[rozsazoltan]

Related:

• Why stop using @apply
• Use alias (by subpath import) for @reference
• How do I use TailwindCSS @apply directive inside a CSS module or in <style>
• How to use @apply in TailwindCSS v4 with Sass?