How to use nested CSS classes in Tailwind CSS v4.1 with CLI compiler (no tailwind.config.js support

[mdtaufiquekhan]

I'm using Tailwind CSS v4.1 with the Tailwind CLI compiler (no tailwind.config.js support in this version). I want to understand the proper way to write nested classes (similar to SCSS nesting or @apply usage) in this setup.

---

What I’ve Tried:

• Installed Tailwind v4.1 via npm.
• Running Tailwind with CLI:

  npx tailwindcss -i ./src/input.css -o ./dist/output.css --watch

Tried writing nested classes using @layer and @apply, but Tailwind throws errors like Unknown at rule @apply.

@layer components{
    .navbar-menu-link{
        @apply block 

        .navbar-menu-child{
            @apply flex
        }
    }
}

My Questions:

1. What’s the recommended way to write nested selectors in Tailwind 4.1 without tailwind.config.js?
2. Does Tailwind v4.1 officially support nesting out-of-the-box, or do I need PostCSS nesting?
3. If PostCSS is required, what’s the correct setup for Tailwind CLI (since v4.1 doesn’t rely on a config file)?
4. Could you provide a small example of how to write a nested rule that compiles correctly with CLI?

[wongjn]

Unknown at rule @apply

This sounds like a warning in VSCode or some other linter, but I don't expect this to be an error from Tailwind itself.

Rather, I see that you haven't terminated the @apply statements with a semi-colon (;):

 @layer components{
   .navbar-menu-link{
-    @apply block 
+    @apply block;

     .navbar-menu-child{
-      @apply flex
+      @apply flex;
     }
   }
 }

---

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

[mdtaufiquekhan]

@wongjn Thank you for your guidance. I realised I made a simple mistake by missing the semicolon. I really appreciate your time and valuable input. I’m just starting to learn Tailwind, so this was a silly mistake on my part.