Tidy gtag snippet indentation

Replace Astro/Strapi site with Next.js static export

src/app/layout.tsx

@@ -58,6 +58,9 @@ const websiteLd = {
   author: { "@type": "Person", name: site.name },
 };
 
+const isProd = process.env.NODE_ENV === "production";
+const gaId = "G-9XLTKZF07C";
+
 const umamiScript = process.env.PUBLIC_UMAMI_SCRIPT_URL;
 const umamiId = process.env.PUBLIC_UMAMI_WEBSITE_ID;
 
@@ -81,7 +84,21 @@ export default function RootLayout({ children }: LayoutProps<"/">) {
       <body>
         <JsonLd data={websiteLd} />
         <Layout>{children}</Layout>
-        {umamiScript && umamiId && (
+        {isProd && (
+          <>
+            <Script
+              src={`https://www.googletagmanager.com/gtag/js?id=${gaId}`}
+              strategy="afterInteractive"
+            />
+            <Script id="google-analytics" strategy="afterInteractive">
+              {`window.dataLayer = window.dataLayer || [];
+function gtag(){dataLayer.push(arguments);}
+gtag('js', new Date());
+gtag('config', '${gaId}');`}
+            </Script>
+          </>
+        )}
+        {isProd && umamiScript && umamiId && (
           <Script defer src={umamiScript} data-website-id={umamiId} />
         )}
       </body>