I couldn't deploy project using this template

[yoryi]

I have worked on this template and would like to deploy to the vercel.
But there were some odd errors that I couldn't find the reason.
First one is for the postcss error. I have not used postcss-discard-comments but it says I have used it. And that is making error when building. As this one is using Tailwind and Postcss 7.0 for compatibility , it says postcss 8.0 needed

Second one is that, it requires the [...slug].js file for the building.
As this is just the NextJs framework, so that I should be able to work without [...slug] for the specific pages like About Page or Contact Us page.
But when building, it requires only [...slug] file for the pages, and I am not sure why.

@gregrickaby Could you please give me some tips for above problems?