diff --git a/Ai-data/prompt-seo.txt b/Ai-data/prompt-seo.txt
index 58cb317..54a55b8 100644
--- a/Ai-data/prompt-seo.txt
+++ b/Ai-data/prompt-seo.txt
@@ -1,9 +1,11 @@
 ### Sitemap + robots.txt
 - Do NOT ship public/sitemap.xml or public/robots.txt (nginx proxies both to Meshkee API).
+- Live sitemap is an index: /sitemap.xml → /sitemap-main.xml + /sitemap-products.xml.
 - Publish GET /meshkee/sitemap-config.json generated at build time from app routes.
 - Include public static routes automatically; exclude auth/checkout/cart/admin paths.
 - Canonical detail URLs (Meshkee defaults — omit templates unless customized):
   - Product: /products/{id}/{nameFaSlug} → GET /tenants/{domain}/products/by-id/{id}
+  - Category: /products/category/{id}/{nameFaSlug} → GET /tenants/{domain}/categories/by-id/{id} (then list products with categoryId)
   - Blog: /blog/{id}/{titleSlug} → GET /tenants/{domain}/blogs/by-id/{id}
   - Portfolio: /portfolios/{id}/{titleFaSlug} → GET /tenants/{domain}/portfolios/by-id/{id}
 - Slugify: Farsi letters kept, spaces → -, strip other punctuation. Do not use legacy DB slug in public URLs.
diff --git a/CONTEXT.md b/CONTEXT.md
index 11e9af3..60c5eef 100644
--- a/CONTEXT.md
+++ b/CONTEXT.md
@@ -40,7 +40,8 @@ This site is **catalog-only** (no shopping cart). Login / user icon goes to the
 | Path | Source |
 | --- | --- |
 | `/` | Homepage + static image slots + store specials + latest blogs |
-| `/products` | Catalog / store items list |
+| `/products` | Catalog / store items list + search (`?q=`) |
+| `/products/category/[id]/[slug]` | Category page via `GET .../categories/by-id/{id}` + products filtered by `categoryId` |
 | `/products/[id]/[slug]` | Product detail via `GET .../products/by-id/{id}` |
 | `/blog` | Blog list |
 | `/blog/[id]/[slug]` | Blog detail via `GET .../blogs/by-id/{id}` |
@@ -68,7 +69,7 @@ Products list/search: prefer store-items; if empty, fall back to `GET /products`
 
 ## Catalog
 
-- Mega menu: product categories **level 1 and 2** (`GET /tenants/{domain}/categories?entityType=product`). Links: `/products?categoryId={id}`.
+- Mega menu: full product category tree (unwraps shallow roots like «کالاها»); nested level-4+ links (`GET /tenants/{domain}/categories?entityType=product`). Links: `/products/category/{id}/{nameFaSlug}`.
 - Instant search: header input searches **products** when query length **> 2** (`/api/search` → `store-items?name=`). Enter or “مشاهده همه” → `/products?q=`.
 - Product pages are display-only (price, gallery, description, comments). No cart / add-to-cart.
 - Details gallery: product `images[].url` + thumbnail. Click = lightbox, hover = zoom.
@@ -98,8 +99,10 @@ Products list/search: prefer store-items; if empty, fall back to `GET /products`
 - After deploy: business dashboard → Website → Settings → Sync sitemap config.
 - Detail URLs (Meshkee defaults — omit `templates` unless customized):
   - Product: `/products/{id}/{nameFaSlug}` — slugify `nameFa` (Farsi kept, spaces → `-`); resolve with `products/by-id/{id}`. Never use legacy DB slug in public URLs.
+  - Category: `/products/category/{id}/{nameFaSlug}` — `categories/by-id/{id}` then list products with that `categoryId`.
   - Blog: `/blog/{id}/{titleSlug}` — `blogs/by-id/{id}`.
-- Legacy `/products/{slug}` and `/blog/{slug}` redirect to the canonical `{id}/{slug}` form.
+- Legacy `/products?categoryId=` and slug-only detail URLs redirect to the canonical `{id}/{slug}` form.
+- Live sitemap is an index: `/sitemap.xml` → `/sitemap-main.xml` + `/sitemap-products.xml` (Meshkee/nginx; do not ship static files).
 - Every public page has unique title/description; product/blog prefer CMS fields.
 
 ## Original business data (do not invent replacements)
diff --git a/app/products/[id]/[slug]/page.tsx b/app/products/[id]/[slug]/page.tsx
index fb7b1de..9ec4b69 100644
--- a/app/products/[id]/[slug]/page.tsx
+++ b/app/products/[id]/[slug]/page.tsx
@@ -149,9 +149,11 @@ export default async function ProductDetailsPage({
                 )}
               </p>
             </div>
-            <p className={`mt-2 text-[13px] ${inStock ? "text-emerald-600" : "text-brand"}`}>
-              {inStock ? "موجود در فروشگاه" : "ناموجود"}
-            </p>
+            {price != null ? (
+              <p className={`mt-2 text-[13px] ${inStock ? "text-emerald-600" : "text-brand"}`}>
+                {inStock ? "موجود در فروشگاه" : "ناموجود"}
+              </p>
+            ) : null}
 
             {variants.length > 1 ? (
               <div className="mt-5 flex flex-wrap gap-2">
diff --git a/app/products/category/[id]/[slug]/page.tsx b/app/products/category/[id]/[slug]/page.tsx
new file mode 100644
index 0000000..ec1e5a0
--- /dev/null
+++ b/app/products/category/[id]/[slug]/page.tsx
@@ -0,0 +1,79 @@
+import type { Metadata } from "next";
+import { notFound, redirect } from "next/navigation";
+import { Container } from "@/components/Container";
+import { PageHero } from "@/components/layout/PageHero";
+import { ProductsListing } from "@/components/products/ProductsListing";
+import {
+  categoryHref,
+  categoryNameSlug,
+  fetchCategoryById,
+} from "@/lib/categories";
+import { loadCategoryProducts } from "@/lib/products-list";
+
+export const revalidate = 60;
+
+export async function generateMetadata({
+  params,
+}: {
+  params: Promise<{ id: string; slug: string }>;
+}): Promise<Metadata> {
+  const { id } = await params;
+  const category = await fetchCategoryById(id);
+  if (!category) return { title: "دسته‌بندی" };
+  const title = category.nameFa?.trim() || category.name?.trim() || "دسته‌بندی";
+  return {
+    title,
+    description: category.description?.trim() || `محصولات دسته ${title} در فروشگاه برادران برقعی`,
+  };
+}
+
+export default async function CategoryProductsPage({
+  params,
+  searchParams,
+}: {
+  params: Promise<{ id: string; slug: string }>;
+  searchParams: Promise<{ page?: string }>;
+}) {
+  const { id, slug } = await params;
+  const { page: pageParam } = await searchParams;
+  const page = Math.max(1, Number(pageParam) || 1);
+
+  const category = await fetchCategoryById(id);
+  if (!category || category.isActive === false) notFound();
+
+  const title = category.nameFa?.trim() || category.name?.trim() || "دسته‌بندی";
+  const canonicalSlug = categoryNameSlug(title);
+  if (decodeURIComponent(slug) !== canonicalSlug) {
+    const href = categoryHref(category);
+    redirect(page > 1 ? `${href}?page=${page}` : href);
+  }
+
+  const { products, total, pageCount } = await loadCategoryProducts({
+    page,
+    pageSize: 20,
+    categoryId: String(category.id),
+  });
+
+  const baseHref = categoryHref(category);
+
+  return (
+    <>
+      <PageHero
+        kicker="Category"
+        title={title}
+        image="/images/lifestyle/franco-debartolo-AXC2vD7y_ho-unsplash.jpg"
+      />
+      <section className="py-10 sm:py-14">
+        <Container>
+          <ProductsListing
+            products={products}
+            total={total}
+            page={page}
+            pageCount={pageCount}
+            pageHref={(number) => (number > 1 ? `${baseHref}?page=${number}` : baseHref)}
+          />
+        </Container>
+      </section>
+    </>
+  );
+}
diff --git a/app/products/page.tsx b/app/products/page.tsx
index 04c5642..420a852 100644
--- a/app/products/page.tsx
+++ b/app/products/page.tsx
@@ -1,16 +1,10 @@
 import type { Metadata } from "next";
-import Link from "next/link";
+import { redirect } from "next/navigation";
 import { Container } from "@/components/Container";
 import { PageHero } from "@/components/layout/PageHero";
-import { ProductCard } from "@/components/ui/ProductCard";
-import { getNavCategories } from "@/lib/categories";
-import { faDigits } from "@/lib/format";
-import {
-  catalogProductToCard,
-  fetchCatalogProducts,
-  fetchStoreItems,
-  variantToProduct,
-} from "@/lib/store";
+import { ProductsListing } from "@/components/products/ProductsListing";
+import { categoryHref, fetchCategoryById } from "@/lib/categories";
+import { loadCategoryProducts } from "@/lib/products-list";
 
 export const revalidate = 60;
 
@@ -30,21 +24,21 @@ export default async function ProductsPage({
   const q = params.q?.trim();
   const name = q && q.length > 2 ? q : undefined;
 
-  const [storeResult, catalogResult, nav] = await Promise.all([
-    fetchStoreItems({ page, pageSize: 20, categoryId, name }),
-    fetchCatalogProducts({ page, pageSize: 20, categoryId, name }),
-    getNavCategories(),
-  ]);
+  // Legacy ?categoryId= → canonical /products/category/{id}/{slug}
+  if (categoryId) {
+    const category = await fetchCategoryById(categoryId);
+    if (category) {
+      const href = categoryHref(category);
+      const query = new URLSearchParams();
+      if (page > 1) query.set("page", String(page));
+      if (q) query.set("q", q);
+      const qs = query.toString();
+      redirect(qs ? `${href}?${qs}` : href);
+    }
+  }
 
-  const fromStore = storeResult.items.map(variantToProduct);
-  const products = fromStore.length ? fromStore : catalogResult.items.map(catalogProductToCard);
-  const total = fromStore.length ? storeResult.total : catalogResult.total;
-  const pageSize = fromStore.length ? storeResult.pageSize : catalogResult.pageSize;
-  const pageCount = Math.max(1, Math.ceil((total || products.length) / (pageSize || 20)));
-  const categoryTitle = nav
-    .flatMap((item) => [item, ...item.children.map((child) => ({ ...child, children: [] as never[] }))])
-    .find((item) => item.id === categoryId)?.title;
-  const heroTitle = categoryTitle || (q ? `جستجو: ${q}` : "محصولات");
+  const { products, total, pageCount } = await loadCategoryProducts({ page, pageSize: 20, name });
+  const heroTitle = q ? `جستجو: ${q}` : "محصولات";
 
   return (
     <>
@@ -55,41 +49,19 @@ export default async function ProductsPage({
       />
       <section className="py-10 sm:py-14">
         <Container>
-          {total ? <p className="mb-6 text-[13px] text-muted">{faDigits(total)} کالا</p> : null}
-
-          {products.length === 0 ? (
-            <div className="rounded-2xl border border-line bg-white px-6 py-16 text-center">
-              <p className="text-[15px] font-bold text-ink">محصولی برای نمایش وجود ندارد</p>
-              <p className="mt-2 text-[13px] text-muted">به‌زودی موجودی فروشگاه از پنل Meshkee اینجا دیده می‌شود.</p>
-            </div>
-          ) : (
-            <div className="grid grid-cols-2 gap-3 md:grid-cols-3 lg:grid-cols-4 xl:grid-cols-5">
-              {products.map((product) => (
-                <ProductCard key={product.id} product={product} />
-              ))}
-            </div>
-          )}
-
-          {pageCount > 1 ? (
-            <div className="mt-8 flex justify-center gap-2">
-              {Array.from({ length: pageCount }, (_, index) => {
-                const number = index + 1;
-                const query = new URLSearchParams();
-                if (categoryId) query.set("categoryId", categoryId);
-                if (q) query.set("q", q);
-                query.set("page", String(number));
-                return (
-                  <Link
-                    key={number}
-                    href={`/products?${query.toString()}`}
-                    className={`grid size-10 place-items-center rounded-xl text-[13px] ${number === page ? "bg-brand text-white" : "border border-line bg-white text-ink"}`}
-                  >
-                    {faDigits(number)}
-                  </Link>
-                );
-              })}
-            </div>
-          ) : null}
+          <ProductsListing
+            products={products}
+            total={total}
+            page={page}
+            pageCount={pageCount}
+            pageHref={(number) => {
+              const query = new URLSearchParams();
+              if (q) query.set("q", q);
+              if (number > 1) query.set("page", String(number));
+              const qs = query.toString();
+              return qs ? `/products?${qs}` : "/products";
+            }}
+          />
         </Container>
       </section>
     </>
diff --git a/components/layout/Header.tsx b/components/layout/Header.tsx
index c4698ff..968bf13 100644
--- a/components/layout/Header.tsx
+++ b/components/layout/Header.tsx
@@ -32,17 +32,17 @@ export function Header({ categories = [] }: { categories?: NavCategory[] }) {
           <Placeholder src={site.logo} alt={site.name} className="h-14 w-auto object-contain" />
         </Link>
 
-        <nav className="mx-2 hidden items-center lg:flex">
-          <Link href="/" className="px-3 py-2 text-[14px] hover:text-brand">
+        <nav className="mx-2 hidden h-14 items-center lg:flex">
+          <Link href="/" className="inline-flex h-full items-center px-3 text-[14px] hover:text-brand">
             خانه
           </Link>
 
           <div
-            className="relative"
+            className="relative flex h-full items-center"
             onMouseEnter={() => setMegaOpen(true)}
             onMouseLeave={() => setMegaOpen(false)}
           >
-            <Link href="/products" className="flex items-center gap-1 px-3 py-2 text-[14px] hover:text-brand">
+            <Link href="/products" className="inline-flex h-full items-center gap-1 px-3 text-[14px] hover:text-brand">
               محصولات
               <ChevronDown className="size-3.5" />
             </Link>
@@ -52,7 +52,11 @@ export function Header({ categories = [] }: { categories?: NavCategory[] }) {
           {navLinks
             .filter((link) => link.href !== "/" && link.href !== "/products")
             .map((link) => (
-              <Link key={link.href} href={link.href} className="px-3 py-2 text-[14px] hover:text-brand">
+              <Link
+                key={link.href}
+                href={link.href}
+                className="inline-flex h-full items-center px-3 text-[14px] hover:text-brand"
+              >
                 {link.label}
               </Link>
             ))}
@@ -107,14 +111,25 @@ export function Header({ categories = [] }: { categories?: NavCategory[] }) {
                         {category.title}
                       </Link>
                       {category.children.map((child) => (
-                        <Link
-                          key={child.id}
-                          href={child.href}
-                          className="block py-1 text-[12px] text-muted"
-                          onClick={() => setOpen(false)}
-                        >
-                          {child.title}
-                        </Link>
+                        <div key={child.id} className="ps-2">
+                          <Link
+                            href={child.href}
+                            className="block py-1 text-[12px] font-medium text-ink"
+                            onClick={() => setOpen(false)}
+                          >
+                            {child.title}
+                          </Link>
+                          {child.children.map((leaf) => (
+                            <Link
+                              key={leaf.id}
+                              href={leaf.href}
+                              className="block py-1 ps-3 text-[12px] text-muted"
+                              onClick={() => setOpen(false)}
+                            >
+                              {leaf.title}
+                            </Link>
+                          ))}
+                        </div>
                       ))}
                     </div>
                   ))
diff --git a/components/layout/MegaMenu.tsx b/components/layout/MegaMenu.tsx
index 3779031..b3e19f5 100644
--- a/components/layout/MegaMenu.tsx
+++ b/components/layout/MegaMenu.tsx
@@ -1,44 +1,56 @@
 "use client";
 
 import Link from "next/link";
-import { Placeholder } from "@/components/Placeholder";
-import type { NavCategory } from "@/lib/categories";
+import { toMegaSections, type NavCategory } from "@/lib/categories";
+
+function CategoryLinks({ items, depth = 0 }: { items: NavCategory[]; depth?: number }) {
+  if (!items.length) return null;
+
+  return (
+    <ul className={depth === 0 ? "space-y-1" : "mt-1 space-y-1 border-r border-line/70 pr-2 mr-1"}>
+      {items.map((item) => (
+        <li key={item.id}>
+          <Link
+            href={item.href}
+            className={`block rounded-lg px-2 py-1 transition hover:bg-paper hover:text-brand ${
+              depth === 0 ? "text-[12.5px] text-muted" : "text-[12px] text-muted/90"
+            }`}
+          >
+            {item.title}
+          </Link>
+          {item.children.length ? <CategoryLinks items={item.children} depth={depth + 1} /> : null}
+        </li>
+      ))}
+    </ul>
+  );
+}
 
 export function MegaMenu({ open, categories }: { open: boolean; categories: NavCategory[] }) {
   if (!open) return null;
 
+  const sections = toMegaSections(categories);
+
   return (
-    <div className="absolute top-full right-0 z-50 mt-1 w-[min(920px,calc(100vw-2rem))] border border-line bg-white p-5 shadow-[0_20px_50px_rgba(0,0,0,0.08)]">
-      {categories.length === 0 ? (
-        <p className="text-[13px] text-muted">دسته‌بندی‌ها به‌زودی اضافه می‌شوند.</p>
-      ) : (
-        <div className="grid grid-cols-2 gap-5 md:grid-cols-3 lg:grid-cols-4">
-          {categories.map((category) => (
-            <div key={category.id}>
-              <Link href={category.href} className="mb-3 flex items-center gap-2 text-[13.5px] font-semibold text-ink hover:text-brand">
-                <span className="grid size-9 place-items-center overflow-hidden rounded-xl bg-paper">
-                  <Placeholder src={category.image || "/placeholders/category.svg"} className="size-full object-cover" />
-                </span>
-                {category.title}
-              </Link>
-              {category.children.length ? (
-                <ul className="space-y-1.5 pr-1">
-                  {category.children.map((child) => (
-                    <li key={child.id}>
-                      <Link
-                        href={child.href}
-                        className="block rounded-lg px-2 py-1 text-[12.5px] text-muted transition hover:bg-paper hover:text-brand"
-                      >
-                        {child.title}
-                      </Link>
-                    </li>
-                  ))}
-                </ul>
-              ) : null}
-            </div>
-          ))}
-        </div>
-      )}
+    <div className="absolute top-full right-0 z-50 -mt-1 pt-3">
+      <div className="max-h-[min(70vh,640px)] w-[min(920px,calc(100vw-2rem))] overflow-y-auto border border-line bg-white p-5 shadow-[0_20px_50px_rgba(0,0,0,0.08)]">
+        {sections.length === 0 ? (
+          <p className="text-[13px] text-muted">دسته‌بندی‌ها به‌زودی اضافه می‌شوند.</p>
+        ) : (
+          <div className="columns-2 gap-6 md:columns-3 lg:columns-4">
+            {sections.map((category) => (
+              <div key={category.id} className="mb-6 break-inside-avoid">
+                <Link
+                  href={category.href}
+                  className="mb-2 block text-[13.5px] font-semibold text-ink hover:text-brand"
+                >
+                  {category.title}
+                </Link>
+                <CategoryLinks items={category.children} />
+              </div>
+            ))}
+          </div>
+        )}
+      </div>
     </div>
   );
 }
diff --git a/components/products/ProductsListing.tsx b/components/products/ProductsListing.tsx
new file mode 100644
index 0000000..74ca568
--- /dev/null
+++ b/components/products/ProductsListing.tsx
@@ -0,0 +1,54 @@
+import Link from "next/link";
+import { ProductCard } from "@/components/ui/ProductCard";
+import { faDigits } from "@/lib/format";
+import type { Product } from "@/lib/data";
+
+export function ProductsListing({
+  products,
+  total,
+  page,
+  pageCount,
+  pageHref,
+}: {
+  products: Product[];
+  total: number;
+  page: number;
+  pageCount: number;
+  pageHref: (page: number) => string;
+}) {
+  return (
+    <>
+      {total ? <p className="mb-6 text-[13px] text-muted">{faDigits(total)} کالا</p> : null}
+
+      {products.length === 0 ? (
+        <div className="rounded-2xl border border-line bg-white px-6 py-16 text-center">
+          <p className="text-[15px] font-bold text-ink">محصولی برای نمایش وجود ندارد</p>
+          <p className="mt-2 text-[13px] text-muted">به‌زودی موجودی فروشگاه از پنل Meshkee اینجا دیده می‌شود.</p>
+        </div>
+      ) : (
+        <div className="grid grid-cols-2 gap-3 md:grid-cols-3 lg:grid-cols-4 xl:grid-cols-5">
+          {products.map((product) => (
+            <ProductCard key={product.id} product={product} />
+          ))}
+        </div>
+      )}
+
+      {pageCount > 1 ? (
+        <div className="mt-8 flex justify-center gap-2">
+          {Array.from({ length: pageCount }, (_, index) => {
+            const number = index + 1;
+            return (
+              <Link
+                key={number}
+                href={pageHref(number)}
+                className={`grid size-10 place-items-center rounded-xl text-[13px] ${number === page ? "bg-brand text-white" : "border border-line bg-white text-ink"}`}
+              >
+                {faDigits(number)}
+              </Link>
+            );
+          })}
+        </div>
+      ) : null}
+    </>
+  );
+}
diff --git a/lib/categories.ts b/lib/categories.ts
index 80ebb33..3e62325 100644
--- a/lib/categories.ts
+++ b/lib/categories.ts
@@ -1,4 +1,5 @@
 import { meshkeeGet, tenantPath } from "@/lib/meshkee";
+import { detailPath, slugifyForUrl } from "@/lib/seo-slug";
 
 export type ApiCategory = {
   id: string;
@@ -6,6 +7,7 @@ export type ApiCategory = {
   name?: string | null;
   nameFa?: string | null;
   slug?: string | null;
+  description?: string | null;
   sortOrder?: number | null;
   isActive?: boolean;
 };
@@ -15,15 +17,20 @@ export type NavCategory = {
   title: string;
   href: string;
   image?: string;
-  children: { id: string; title: string; href: string }[];
+  children: NavCategory[];
 };
 
-function titleOf(category: ApiCategory) {
-  return category.nameFa?.trim() || category.name?.trim() || "دسته‌بندی";
+function titleOf(category: Pick<ApiCategory, "nameFa" | "name" | "id">) {
+  return category.nameFa?.trim() || category.name?.trim() || String(category.id);
 }
 
-function hrefOf(category: ApiCategory) {
-  return `/products?categoryId=${encodeURIComponent(category.id)}`;
+/** Public category URL: /products/category/{id}/{nameFaSlug} */
+export function categoryHref(category: Pick<ApiCategory, "id" | "nameFa" | "name">) {
+  return detailPath("/products/category", category.id, titleOf(category));
+}
+
+export function categoryNameSlug(title: string) {
+  return slugifyForUrl(title);
 }
 
 export async function fetchProductCategories() {
@@ -33,6 +40,14 @@ export async function fetchProductCategories() {
   return (data.items ?? []).filter((category) => category.isActive !== false);
 }
 
+export async function fetchCategoryById(categoryId: string) {
+  const data = await meshkeeGet<{ category?: ApiCategory }>(
+    tenantPath(`/categories/by-id/${encodeURIComponent(categoryId)}`),
+    {},
+  );
+  return data.category ?? null;
+}
+
 export function buildCategoryTree(flat: ApiCategory[]): NavCategory[] {
   const byId = new Map(flat.map((category) => [String(category.id), category]));
   const children = new Map<string, ApiCategory[]>();
@@ -48,18 +63,70 @@ export function buildCategoryTree(flat: ApiCategory[]): NavCategory[] {
   const sort = (list: ApiCategory[]) =>
     [...list].sort((a, b) => (a.sortOrder ?? 0) - (b.sortOrder ?? 0) || titleOf(a).localeCompare(titleOf(b), "fa"));
 
-  return sort(children.get("root") ?? []).map((root) => ({
-    id: String(root.id),
-    title: titleOf(root),
-    href: hrefOf(root),
-    children: sort(children.get(String(root.id)) ?? []).map((child) => ({
-      id: String(child.id),
-      title: titleOf(child),
-      href: hrefOf(child),
-    })),
-  }));
+  const build = (category: ApiCategory): NavCategory => ({
+    id: String(category.id),
+    title: titleOf(category),
+    href: categoryHref(category),
+    children: sort(children.get(String(category.id)) ?? []).map(build),
+  });
+
+  return sort(children.get("root") ?? []).map(build);
+}
+
+/** Skip single-child wrapper roots (e.g. کالاها → لوازم…) so mega menu starts at useful columns. */
+export function unwrapNavRoots(nodes: NavCategory[]): NavCategory[] {
+  let current = nodes;
+  while (current.length === 1 && current[0].children.length > 0) {
+    current = current[0].children;
+  }
+  return current;
+}
+
+export function flattenNavCategories(nodes: NavCategory[]): NavCategory[] {
+  const result: NavCategory[] = [];
+  const walk = (list: NavCategory[]) => {
+    for (const node of list) {
+      result.push(node);
+      if (node.children.length) walk(node.children);
+    }
+  };
+  walk(nodes);
+  return result;
+}
+
+export function findNavCategory(nodes: NavCategory[], id?: string | null) {
+  if (!id) return undefined;
+  return flattenNavCategories(nodes).find((item) => item.id === id);
+}
+
+/**
+ * Flatten one level for the mega menu: nested groups become sibling sections
+ * so CSS columns can pack them evenly.
+ */
+export function toMegaSections(categories: NavCategory[]): NavCategory[] {
+  const sections: NavCategory[] = [];
+
+  for (const category of categories) {
+    const leaves = category.children.filter((child) => child.children.length === 0);
+    const branches = category.children.filter((child) => child.children.length > 0);
+
+    if (!branches.length) {
+      sections.push(category);
+      continue;
+    }
+
+    if (leaves.length) {
+      sections.push({ ...category, children: leaves });
+    }
+
+    for (const branch of branches) {
+      sections.push(branch);
+    }
+  }
+
+  return sections;
 }
 
 export async function getNavCategories() {
-  return buildCategoryTree(await fetchProductCategories());
+  return unwrapNavRoots(buildCategoryTree(await fetchProductCategories()));
 }
diff --git a/lib/products-list.ts b/lib/products-list.ts
new file mode 100644
index 0000000..b72d3ad
--- /dev/null
+++ b/lib/products-list.ts
@@ -0,0 +1,41 @@
+import type { Product } from "@/lib/data";
+import {
+  catalogProductToCard,
+  fetchCatalogProducts,
+  fetchStoreItems,
+  variantToProduct,
+} from "@/lib/store";
+
+export async function loadCategoryProducts(params: {
+  page?: number;
+  pageSize?: number;
+  categoryId?: string;
+  name?: string;
+}) {
+  const page = params.page ?? 1;
+  const pageSize = params.pageSize ?? 20;
+  const [storeResult, catalogResult] = await Promise.all([
+    fetchStoreItems({
+      page,
+      pageSize,
+      categoryId: params.categoryId,
+      name: params.name,
+    }),
+    fetchCatalogProducts({
+      page,
+      pageSize,
+      categoryId: params.categoryId,
+      name: params.name,
+    }),
+  ]);
+
+  const fromStore = storeResult.items.map(variantToProduct);
+  const products: Product[] = fromStore.length
+    ? fromStore
+    : catalogResult.items.map(catalogProductToCard);
+  const total = fromStore.length ? storeResult.total : catalogResult.total;
+  const resolvedPageSize = fromStore.length ? storeResult.pageSize : catalogResult.pageSize;
+  const pageCount = Math.max(1, Math.ceil((total || products.length) / (resolvedPageSize || pageSize)));
+
+  return { products, total, pageCount, pageSize: resolvedPageSize || pageSize };
+}
diff --git a/lib/store.ts b/lib/store.ts
index 52ad061..2599bb1 100644
--- a/lib/store.ts
+++ b/lib/store.ts
@@ -255,7 +255,7 @@ export function catalogProductToCard(product: CatalogProduct): Product {
     id: String(product.id),
     href: productHref(product),
     title: catalogTitle(product),
-    brand: brandName(product) || product.categoryNameFa || "",
+    brand: brandName(product),
     price: price ?? undefined,
     image: product.thumbnailUrl || product.image || product.thumbnail || PLACEHOLDER,
     inStock: product.store?.inStock !== false,