Hi Peter.
Generalising SPPB use styles based on Bootstrap, this same as Joomla 5/6 core itself. It means that we don't offer support for Tailwind CSS. And this is unlikely to change in the coming months.
Bootstrap and Tailwind CSS represent two different approaches to creating website designs. Bootstrap offers a set of ready-made components and predefined styles, allowing you to quickly build responsive layouts. Tailwind CSS, on the other hand, is based on a utility-first philosophy, allowing you to precisely customise each element using small utility classes directly in the HTML code.