Update showCategory function to handle walkthrough mode

index.html

@@ -1744,6 +1744,12 @@
                 return;
             }
             
+            if (categoryId === 'walkthrough') {
+                mainMenu.style.display = 'none';
+                document.getElementById('walkthroughMode').style.display = 'block';
+                return;
+            }
+            
             const category = CATEGORIES[categoryId];
             categoryTitle.textContent = category.title;
             categorySubtitle.textContent = category.subtitle;