feat: Update version to 2.2.3 and enhance styling in MegaMenu

classic/megamenu-classic.css

@@ -1,4 +1,4 @@
-/* SharePoint MegaMenu 2.2.0 - Classic pages */
+/* SharePoint MegaMenu 2.2.3 - Classic pages */
 :root {
     --megaMenuBarHeight: 44px;
     --megaMenuContentWidth: 1200px;
@@ -8,10 +8,13 @@
 
 .megamenu-classic-container {
     position: relative;
+    box-sizing: border-box;
     width: 100%;
     margin: 0;
     padding: 0;
     overflow: visible;
+    border-top: 1px solid #edebe9;
+    border-bottom: 1px solid #edebe9;
     z-index: var(--megaMenuZIndex);
     font-family: "Segoe UI", Arial, sans-serif;
 }
@@ -22,8 +25,8 @@
     width: 100%;
     min-height: var(--megaMenuBarHeight);
     overflow: visible;
-    border-top: 1px solid #edebe9;
-    border-bottom: 1px solid #edebe9;
+    border-top: 0;
+    border-bottom: 0;
     background: #fff;
     color: #323130;
 }