Hey!
The documentation needs some updates in the Disable Preflight section, explaining how to add advanced config without @import "tailwindcss";"
I gathered some config infos here and here.
How to use source(none) without preflight:
@layer theme, base, components, utilities;
@import "tailwindcss/theme.css" layer(theme);
@import "tailwindcss/utilities.css" layer(utilities) source(none);
 
How to use theme(static) without preflight: (always output all variables)
@layer theme, base, components, utilities;
@import "tailwindcss/theme.css" layer(theme) theme(static);
@import "tailwindcss/utilities.css" layer(utilities);
 
How to use prefix(tw) without preflight:
@layer theme, base, components, utilities;
@import "tailwindcss/theme.css" layer(theme) prefix(tw);
@import "tailwindcss/utilities.css" layer(utilities);
 
How to use important without preflight:
@layer theme, base, components, utilities;
@import "tailwindcss/theme.css" layer(theme);
@import "tailwindcss/utilities.css" layer(utilities) important;