Fix mobile header flickering issue

Fixes #1391

Update the `Navbar` component to use responsive Tailwind classes for mobile and desktop layouts.

* Remove the `useIsMobile` hook import from `src/components/Header/Navbar.component.tsx`.
* Replace the conditional rendering in `Navbar` with responsive Tailwind classes.
* Delete the `src/utils/hooks/useIsMobile.ts` file.

---

For more details, open the [Copilot Workspace session](https://copilot-workspace.githubnext.com/w3bdesign/nextjs-woocommerce/issues/1391?shareId=XXXX-XXXX-XXXX-XXXX).

Author: w3bdesign

src/components/Header/Navbar.component.tsx

@@ -1,70 +1,59 @@
-// Imports
 import Link from 'next/link';
 
-// Components
 import Cart from './Cart.component';
 import AlgoliaSearchBox from '../AlgoliaSearch/AlgoliaSearchBox.component';
 import MobileSearch from '../AlgoliaSearch/MobileSearch.component';
 
-// Utils
-import useIsMobile from '@/utils/hooks/useIsMobile';
-
 /**
  * Navigation for the application.
  * Includes mobile menu.
  */
 const Navbar = () => {
-  const isMobile = useIsMobile();
   return (
     <header className="border-b border-gray-200">
       <nav id="header" className="top-0 z-50 w-full bg-white">
         <div className="container mx-auto px-4 sm:px-6 py-4">
-          {isMobile ? (
-            // Mobile layout - logo with search below
-            <div className="flex flex-col space-y-4">
-              <div className="text-center">
-                <Link href="/">
-                  <span className="text-lg font-bold tracking-widest text-gray-900">
-                    NETTBUTIKK
-                  </span>
-                </Link>
-              </div>
-              <div className="w-full">
-                <MobileSearch />
-              </div>
+          <div className="flex flex-col space-y-4 md:hidden">
+            <div className="text-center">
+              <Link href="/">
+                <span className="text-lg font-bold tracking-widest text-gray-900">
+                  NETTBUTIKK
+                </span>
+              </Link>
             </div>
-          ) : (
-            // Desktop layout
-            <div className="flex items-center justify-between">
-              <div className="flex items-center space-x-8">
-                <Link href="/produkter">
-                  <span className="text-base uppercase tracking-wider group relative">
-                    <span className="relative inline-block">
-                      <span className="absolute -bottom-1 left-0 w-0 h-px bg-gray-900 group-hover:w-full transition-all duration-500"></span>
-                      Produkter
-                    </span>
+            <div className="w-full">
+              <MobileSearch />
+            </div>
+          </div>
+          <div className="hidden md:flex items-center justify-between">
+            <div className="flex items-center space-x-8">
+              <Link href="/produkter">
+                <span className="text-base uppercase tracking-wider group relative">
+                  <span className="relative inline-block">
+                    <span className="absolute -bottom-1 left-0 w-0 h-px bg-gray-900 group-hover:w-full transition-all duration-500"></span>
+                    Produkter
                   </span>
-                </Link>
-                <Link href="/kategorier">
-                  <span className="text-base uppercase tracking-wider group relative">
-                    <span className="relative inline-block">
-                      <span className="absolute -bottom-1 left-0 w-0 h-px bg-gray-900 group-hover:w-full transition-all duration-500"></span>
-                      Kategorier
-                    </span>
+                </span>
+              </Link>
+              <Link href="/kategorier">
+                <span className="text-base uppercase tracking-wider group relative">
+                  <span className="relative inline-block">
+                    <span className="absolute -bottom-1 left-0 w-0 h-px bg-gray-900 group-hover:w-full transition-all duration-500"></span>
+                    Kategorier
                   </span>
-                </Link>
-              </div>
-              <Link href="/" className="hidden lg:block">
-                <span className="text-xl font-bold tracking-widest text-gray-900 hover:text-gray-700 transition-colors">
-                  NETTBUTIKK
                 </span>
               </Link>
-              <div className="flex items-center space-x-3">
-                <AlgoliaSearchBox />
-                <Cart />
-              </div>
             </div>
-          )}
+            <Link href="/" className="hidden lg:block">
+              <span className="text-xl font-bold tracking-widest text-gray-900 hover:text-gray-700 transition-colors">
+                NETTBUTIKK
+              </span>
+            </Link>
+            <div className="flex items-center space-x-3">
+              <AlgoliaSearchBox />
+              <Cart />
+            </div>
+          </div>
         </div>
       </nav>
     </header>