diff --git a/src/app/pages/category/._subcategories.component.html b/src/app/pages/category/._subcategories.component.html
new file mode 100644
index 0000000..707ba9b
Binary files /dev/null and b/src/app/pages/category/._subcategories.component.html differ
diff --git a/src/app/pages/category/category.component.ts b/src/app/pages/category/category.component.ts
index e7c13dd..3b7701c 100644
--- a/src/app/pages/category/category.component.ts
+++ b/src/app/pages/category/category.component.ts
@@ -40,9 +40,10 @@ export class CategoryComponent implements OnInit, OnDestroy {
 
   ngOnInit(): void {
     this.routeSubscription = this.route.params.subscribe(params => {
-      const id = Number.parseInt(params['id'], 10);
+      const rawId = params['id'];
+      const id = Number(rawId);
 
-      if (!Number.isFinite(id) || id <= 0) {
+      if (!Number.isInteger(id) || id <= 0 || String(id) !== String(rawId)) {
         this.error.set('Invalid category ID');
         this.items.set([]);
         this.hasMore.set(false);
diff --git a/src/app/pages/category/subcategories.component.html b/src/app/pages/category/subcategories.component.html
index 28c977a..0800d93 100644
--- a/src/app/pages/category/subcategories.component.html
+++ b/src/app/pages/category/subcategories.component.html
@@ -22,7 +22,11 @@
     @if (nestedSubcategories().length > 0) {
       <div class="categories-grid">
         @for (sub of nestedSubcategories(); track trackBySubId($index, sub)) {
-          <a [routerLink]="['/category', sub.id] | langRoute" class="category-card">
+          @if (getSubcategoryRouteId(sub) !== null) {
+            <a [routerLink]="['/category', getSubcategoryRouteId(sub)] | langRoute" class="category-card">
+          } else {
+            <div class="category-card category-card--disabled">
+          }
             <div class="category-image">
               @if (sub.img) {
                 <img [src]="sub.img" [alt]="sub.name" loading="lazy" decoding="async" />
@@ -36,7 +40,11 @@
                 <span class="category-count">{{ sub.itemCount }}</span>
               }
             </div>
-          </a>
+          @if (getSubcategoryRouteId(sub) !== null) {
+            </a>
+          } else {
+            </div>
+          }
         }
       </div>
     }
diff --git a/src/app/pages/category/subcategories.component.ts b/src/app/pages/category/subcategories.component.ts
index 805963f..793341c 100644
--- a/src/app/pages/category/subcategories.component.ts
+++ b/src/app/pages/category/subcategories.component.ts
@@ -41,9 +41,10 @@ export class SubcategoriesComponent implements OnInit, OnDestroy {
 
   ngOnInit(): void {
     this.routeSubscription = this.route.params.subscribe(params => {
-      const id = Number.parseInt(params['id'], 10);
+      const rawId = params['id'];
+      const id = Number(rawId);
 
-      if (!Number.isFinite(id) || id <= 0) {
+      if (!Number.isInteger(id) || id <= 0 || String(id) !== String(rawId)) {
         this.error.set('Invalid category ID');
         this.categories.set([]);
         this.subcategories.set([]);
@@ -140,6 +141,15 @@ export class SubcategoriesComponent implements OnInit, OnDestroy {
     return sub.id;
   }
 
+  getSubcategoryRouteId(sub: Subcategory): number | null {
+    if (!sub?.id) return null;
+    const id = Number(sub.id);
+    if (!Number.isInteger(id) || id <= 0 || String(id) !== String(sub.id)) {
+      return null;
+    }
+    return id;
+  }
+
   readonly getDiscountedPrice = getDiscountedPrice;
   readonly getMainImage = getMainImage;
   readonly trackByItemId = trackByItemId;
diff --git a/src/app/services/._api.service.ts b/src/app/services/._api.service.ts
new file mode 100644
index 0000000..707ba9b
Binary files /dev/null and b/src/app/services/._api.service.ts differ
diff --git a/src/app/services/api.service.ts b/src/app/services/api.service.ts
index ef45d1b..1cde4a2 100644
--- a/src/app/services/api.service.ts
+++ b/src/app/services/api.service.ts
@@ -1,6 +1,6 @@
 import { Injectable } from '@angular/core';
 import { HttpClient, HttpParams } from '@angular/common/http';
-import { Observable, timer } from 'rxjs';
+import { Observable, timer, throwError } from 'rxjs';
 import { map, retry } from 'rxjs/operators';
 import { Category, Item, Subcategory } from '../models';
 import { environment } from '../../environments/environment';
@@ -267,6 +267,10 @@ export class ApiService {
   }
 
   getCategoryItems(categoryID: number, count: number = 50, skip: number = 0): Observable<Item[]> {
+    if (!Number.isInteger(categoryID) || categoryID <= 0) {
+      return throwError(() => new Error('Invalid category ID')); 
+    }
+
     const params = new HttpParams()
       .set('count', count.toString())
       .set('skip', skip.toString());