style: adjust USP grid to accommodate 3 items

proto/dev.log

@@ -42,3 +42,6 @@
  GET / 200 in 49ms
  GET / 200 in 35ms
  GET / 200 in 33ms
+ ✓ Compiled / in 25ms
+ ⚠ metadataBase property in metadata export is not set for resolving social open graph or twitter images, using "http://localhost:3000". See https://nextjs.org/docs/app/api-reference/functions/generate-metadata#metadatabase
+ GET / 200 in 202ms

proto/src/app/page.tsx

@@ -93,7 +93,7 @@ export default function Home() {
             {pageContent.about.title}
             </h2>
           </div>
-          <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-4 gap-6 stagger-children">
+          <div className="grid grid-cols-1 md:grid-cols-3 gap-8 max-w-5xl mx-auto stagger-children">
             {pageContent.about.usps.map((usp: any, index: number) => (
               <div 
                 key={usp.id}