Improve homepage Lighthouse performance

css/pages/_home.css

@@ -937,4 +937,11 @@
         box-sizing: border-box;
         padding: 32px 20px;
     }
-}
+}
+
+/* The phone crop keeps the desktop framing while avoiding off-screen image bytes. */
+@media (max-width: 480px) {
+    .hero-background {
+        background-image: url('../../images/HeroSection-img1-mobile.webp');
+    }
+}