next.config.js

/**
 * @type {import('next').NextConfig}
 */
module.exports = {
  reactStrictMode: true,
  poweredByHeader: false,
  compiler: {
    styledComponents: true
  },
  async headers() {
    return [
      {
        source: '/(.*)',
        headers: securityHeaders
      }
    ]
  }
}

const ContentSecurityPolicy = `
  default-src 'self';
  script-src 'self' 'unsafe-eval' 'unsafe-inline';
  style-src 'self' 'unsafe-inline';
  img-src * blob: data:;
  connect-src *;
  font-src 'self';
`

const securityHeaders = [
  {
    key: 'Content-Security-Policy',
    value: ContentSecurityPolicy.replace(/\n/g, '')
  },
  {
    key: 'Referrer-Policy',
    value: 'strict-origin-when-cross-origin'
  },
  {
    key: 'X-Content-Type-Options',
    value: 'nosniff'
  },
  {
    key: 'X-DNS-Prefetch-Control',
    value: 'on'
  },
  {
    key: 'Strict-Transport-Security',
    value: 'max-age=31536000; includeSubDomains; preload'
  },
  {
    key: 'Permissions-Policy',
    value: 'camera=(), microphone=(), geolocation=(), interest-cohort=()'
  }
]