- Use inline opacity (0.15) on poster image — Tailwind opacity-20 not
  applying in production build
- Add color-scheme: dark meta tag for browser/reader mode compatibility
- Set html/body background to #0a0a0a to prevent white bleed
- Fix reveal animation: sections visible by default, animate only after
  JS hydration via .reveal-ready class on documentElement
- Bump screenshots script to domcontentloaded + 3s render wait