Minimalist Conversion Calculator Landing Pages

I need automated conversion calculator landing pages built using Next.js and deployed on Vercel. The design should be minimalist.

- Next.js static site hosted on Vercel (free hosting)
- Auto-generate 500+ landing pages (e.g., toolbox.com/2-kg-to-lb)
- Instant answer displayed above fold (no interaction needed)
- Sub-1-second mobile load time
- Schema markup for featured snippets (Calculator, FAQ, Breadcrumbs)
- Clean, ad-free interface optimized for Google AdSense later
- Connect to my IONOS domain (converter-toolkit.com)

DELIVERABLES:
- Fully functional site deployed on Vercel
- First 500 pages auto-generated (kg/lb, celsius/fahrenheit, etc.)
- DNS setup instructions for IONOS
- Admin panel or script to add more conversions easily

PRIORITY CONVERSIONS:
- Weight: kg to lb, lb to kg
- Temperature: Celsius to Fahrenheit, Fahrenheit to Celsius
- Length: cm to inches, inches to cm

I have the full technical brief and SEO strategy ready to share with the selected developer.