Host Tailwind JIT does not scan theme templates, so responsive grid/hero utilities (sm:/md:/lg:grid-cols-*, min-h-screen, arbitrary values) are dropped and multi-column layouts collapse to one column. Ship the load-bearing responsive layout as compiled theme CSS and point the override templates at it. Layout only — colours stay on semantic tokens. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>