Thanks! It seems to be because Tailwind CSS v4.0 is designed for Safari 16.4+, Chrome 111+, and Firefox 128+. https://tailwindcss.com/docs/upgrade-guide https:

Thanks! It seems to be because Tailwind CSS v4.0 is designed for Safari 16.4+, Chrome 111+, and Firefox 128+. https://tailwindcss.com/docs/upgrade-guide https://tailwindcss.com/docs/upgrade-guide Fixing this on old browsers would require refactoring everything to an earlier version of Tailwind, I'll investigate this.