_headers

# HTTP Headers — Netlify / Cloudflare Pages ONLY
#
# GitHub Pages does NOT support custom HTTP headers. This file has no effect there.
# The headers below will activate automatically if you:
#   1. Migrate to Netlify (free) — just connect the same GitHub repo; Netlify reads _headers natively.
#   2. Put Cloudflare (free) in front of GitHub Pages — use Transform Rules to inject these headers.
#
# WHY THIS MATTERS FOR LIGHTHOUSE:
#   - Cache-Control on /Images/* extends TTL from GitHub's forced ~600s to 1 year (fixes "Use efficient cache lifetimes")
#   - X-Frame-Options, CSP, COOP, HSTS push Best Practices from 96 to 100

/*
  X-Frame-Options: SAMEORIGIN
  X-Content-Type-Options: nosniff
  Referrer-Policy: strict-origin-when-cross-origin
  Permissions-Policy: camera=(), microphone=(), geolocation=()
  Cross-Origin-Opener-Policy: same-origin
  Content-Security-Policy: default-src 'self'; script-src 'self' 'unsafe-inline' https://www.googletagmanager.com https://maps.googleapis.com https://maps.gstatic.com https://www.clarity.ms; style-src 'self' 'unsafe-inline' https://fonts.googleapis.com; font-src 'self' https://fonts.gstatic.com; img-src 'self' data: https://maps.googleapis.com https://maps.gstatic.com https://lh3.googleusercontent.com https://www.clarity.ms; frame-src https://www.google.com https://www.googletagmanager.com; connect-src 'self' https://www.google-analytics.com https://formspree.io https://www.googletagmanager.com https://www.clarity.ms; object-src 'none'; base-uri 'self'; form-action 'self' https://formspree.io; frame-ancestors 'self'

# Cache images for 1 year (content-addressed filenames recommended for true immutability)
/Images/*
  Cache-Control: public, max-age=31536000, must-revalidate

# Cache JS and CSS for 1 year
/JS/*
  Cache-Control: public, max-age=31536000, must-revalidate

/CSS/*
  Cache-Control: public, max-age=31536000, must-revalidate

# HTML pages — short cache with revalidation so updates propagate quickly
/*.html
  Cache-Control: public, max-age=300, must-revalidate