**What version of Tailwind CSS are you using?** 4.1.6 **What build tool (or framework if it abstracts the build tool) are you using?** @tailwindcss/vite 4.1.6 **What version of Node.js are you using?** Deno @utility accent-muted { @apply <classes> } @utility accent_muted { @apply <classes> } @utility header-1 { @apply <classes> } will get generated, but @utility header_1 { @apply <classes> } seems won't get generated. Any reason for that?