@apply leading-none with important modifier makes every following leading-none also important

[delphi-sucks]

What version of Tailwind CSS are you using?

v4.1.14

What build tool (or framework if it abstracts the build tool) are you using?

cli

What version of Node.js are you using?

v22.20.0

What browser are you using?

Chrome

What operating system are you using?

Linux

Reproduction URL

https://play.tailwindcss.com/8ALgvPmwvv?file=css

Describe your issue

When using @apply with the utility class leading-none and the important modifier (leading-none!), then every other leading-none after the first usage of important also becomes important.

.c1 {
  @apply leading-none;
}

.c2 {
  @apply leading-none!;
}

.c3 {
  @apply leading-none;
}

will generate

.c1 {
  --tw-leading: 1;
  line-height: 1;
}
.c2 {
  --tw-leading: 1!important;
  line-height: 1!important;
}
.c3 {
  --tw-leading: 1!important;
  line-height: 1!important;
}

[thecrypticace]

Thanks for reporting this! The fix will go out in the next release 👍