move obsolete browser warning from home1.css to home1.js

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

groups/home/bootstrap5/home1.js

@@ -33,6 +33,14 @@
   } catch (e) {}
 })();
 
+// Display warning if ES6 detection failed
+window.onload = function () {
+  if (window.isES6 == false) {
+    document.getElementById("obsolete_browser_alert").innerHTML =
+      '<div class="alert alert-danger" role="alert" style="text-align: center;"><strong>WARNING! Unsupported browser!</strong><br />It looks like you\'re using an old browser.<br />This website works best with modern browsers such as the latest versions of Chrome, Firefox, Safari, and Edge.<br />If you continue with this browser, many parts of this site will not work and you will see unexpected results.</div>';
+  }
+};
+
 const hamburgerComponent = {
   template: `<div class="bigger-fancy-text">
     <i v-bind:class="item.icon" aria-hidden="true"></i>