Next.js: How to change css of root div __next on specific page?

Maybe this helps someone.
create a folder “styles” add “globals.css”

add this to that file

@tailwind components;
@tailwind utilities;
@layer components {
    #__next {
        @apply h-full bg-red-500;
    }
    html,
    body {
        @apply h-full;
    }
}

go to your _app.js and import the above stylesheet.