diff --git a/src/components/InteractiveIndex.tsx b/src/components/InteractiveIndex.tsx
index 4ecc3da..c9f3b9e 100644
--- a/src/components/InteractiveIndex.tsx
+++ b/src/components/InteractiveIndex.tsx
@@ -243,6 +243,15 @@ const allInteractives: Interactive[] = [
     path: '/themes/games/craps-game',
     theme: 'Games',
     dateAdded: '2025-01-05'
+  },
+  {
+    id: 'neighbor-sum-avoidance',
+    title: 'Neighbor Sum Avoidance',
+    description: 'Arrange numbers in a circle so that the sum of two neighbors is never divisible by 3, 5, or 7. An interactive graph theory puzzle!',
+    tags: ['graph-theory', 'puzzle', 'arrangement', 'divisibility', 'circle', 'mathematics'],
+    path: '/themes/discrete-math/graphs/neighbor-sum-avoidance',
+    theme: 'Discrete Math',
+    dateAdded: '2025-01-22'
   }
 ];
 
diff --git a/src/utils/security.ts b/src/utils/security.ts
index a8bb895..7ec7d66 100644
--- a/src/utils/security.ts
+++ b/src/utils/security.ts
@@ -30,8 +30,8 @@ export const sanitizeUrl = (url: string): string => {
   
   try {
     const urlObj = new URL(url);
-    // Remove any potentially harmful query parameters
-    const cleanUrl = `${urlObj.protocol}//${urlObj.host}${urlObj.pathname}`;
+    // Keep the full URL including pathname, search, and hash for proper routing
+    const cleanUrl = `${urlObj.protocol}//${urlObj.host}${urlObj.pathname}${urlObj.search}${urlObj.hash}`;
     return cleanUrl;
   } catch {
     return window.location.href;