Desktop: seller brand header redesign + collections list/detail

- seller: desktop brand header matching the design — cover, overlapping rounded
  logo, name + verified badge + @handle, horizontal stats, Follow/Message
  actions, description; mobile blocks hidden at lg; feed = responsive masonry
- /collections: 4-column card grid on desktop (was a stretched single column)
- /collection/<id>: two-column hero (cover + info) on desktop, contained width,
  mobile header hidden at lg; products use the responsive masonry
- MyLayout: desktop gate now includes /collections and /collection/*

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

app/components/MyLayout.tsx

@@ -35,6 +35,8 @@ const MyLayout = React.memo(({ children }: { children: React.ReactNode }) => {
     p === "/" ||
     p.startsWith("/search/") ||
     p.startsWith("/seller/") ||
+    p === "/collections" ||
+    p.startsWith("/collection/") ||
     p === "/cart";
   // Auth pages get a full-width desktop canvas (so they can center their own
   // card) but no shopping header/footer.

app/routes/collection.$id.tsx

@@ -129,8 +129,8 @@ export default function CollectionDetail() {
 
   return (
     <div className="flex flex-col min-h-screen bg-WHITE pb-20">
-      {/* Header */}
-      <div className="flex flex-row h-[65px] sticky top-0 z-30 bg-WHITE w-full items-center justify-center border-b border-inner-border">
+      {/* Header (mobile) */}
+      <div className="lg:hidden flex flex-row h-[65px] sticky top-0 z-30 bg-WHITE w-full items-center justify-center border-b border-inner-border">
         <ArrowRight
           onClick={handleBack}
           className="absolute top-5 right-5 cursor-pointer"
@@ -139,11 +139,11 @@ export default function CollectionDetail() {
       </div>
 
       {/* Content */}
-      <div className="flex flex-col">
+      <div className="flex flex-col lg:max-w-[1320px] lg:mx-auto lg:w-full lg:px-8 lg:pt-6">
         {/* Collection Header */}
-        <div className="flex flex-col gap-4 p-4 border-b border-inner-border">
+        <div className="flex flex-col gap-4 p-4 border-b border-inner-border lg:grid lg:grid-cols-[1.3fr_1fr] lg:gap-8 lg:items-center lg:p-0 lg:py-8 lg:border-0">
           {/* Cover Image */}
-          <div className="relative overflow-hidden rounded-xl w-full mx-auto h-[65vh] bg-gray-100">
+          <div className="relative overflow-hidden rounded-xl w-full mx-auto h-[65vh] bg-gray-100 lg:h-[460px]">
             {collection.coverImageUrl ? (
               <img
                 src={collection.coverImageUrl}
@@ -159,7 +159,7 @@ export default function CollectionDetail() {
 
           {/* Collection Info */}
           <div className="flex flex-col gap-3">
-            <h1 className="text-B20 font-bold text-black">
+            <h1 className="text-B20 lg:text-[28px] font-bold text-black">
               {collection.title || "بدون عنوان"}
             </h1>
 

app/routes/collections.tsx

@@ -41,7 +41,7 @@ export default function Collections() {
 
   // Loading skeleton
   const CollectionSkeleton = () => (
-    <div className="flex flex-col gap-4 px-4">
+    <div className="flex flex-col gap-4 px-4 lg:grid lg:grid-cols-4 lg:gap-5 lg:px-0">
       {Array.from({ length: 6 }).map((_, index) => (
         <div
           key={index}
@@ -117,8 +117,8 @@ export default function Collections() {
 
   return (
     <div className="flex flex-col bg-WHITE pb-20">
-      {/* Header - مطابق با ProfilePagesHeader */}
-      <div className="flex flex-row h-[65px] sticky top-0 z-30 bg-WHITE w-full items-center justify-center border-b border-inner-border">
+      {/* Header (mobile) */}
+      <div className="lg:hidden flex flex-row h-[65px] sticky top-0 z-30 bg-WHITE w-full items-center justify-center border-b border-inner-border">
         <ArrowRight
           onClick={handleBack}
           className="absolute top-5 right-5 cursor-pointer"
@@ -127,7 +127,10 @@ export default function Collections() {
       </div>
 
       {/* Content */}
-      <div className="flex flex-col py-6">
+      <div className="flex flex-col py-6 lg:max-w-[1320px] lg:mx-auto lg:w-full lg:px-8">
+        <h1 className="hidden lg:block text-[28px] font-extrabold mb-6">
+          کالکشن‌ها
+        </h1>
         {status === "pending" ? (
           <CollectionSkeleton />
         ) : status === "error" ? (
@@ -136,7 +139,7 @@ export default function Collections() {
           <EmptyState />
         ) : (
           <>
-            <div className="flex flex-col gap-4 px-4">
+            <div className="flex flex-col gap-4 px-4 lg:grid lg:grid-cols-4 lg:gap-5 lg:px-0">
               {allCollections.map((collection) => (
                 <Link
                   key={collection.id}

app/routes/seller.$sellerId._index.tsx

@@ -18,6 +18,7 @@ import {
   Check,
   UserMinus,
   Shirt,
+  BadgeCheck,
 } from "lucide-react";
 import HeaderWithSupport from "../components/HeaderWithSupport";
 import { useState, useEffect } from "react";
@@ -192,25 +193,110 @@ export default function Seller() {
       type="seller"
     >
       <div className="flex flex-col pb-20 lg:max-w-[1100px] lg:mx-auto lg:w-full lg:px-8 lg:pt-8">
-        {/* Header */}
-        <div className="relative">
-          <div className="lg:hidden">
-            <HeaderWithSupport
-              title={seller?.storeName || ""}
-              onBack={handleBack}
-            />
+        {/* Desktop brand header (cover + overlapping logo + stats + actions) */}
+        <div className="hidden lg:block">
+          <div className="relative h-[200px] rounded-[22px] overflow-hidden bg-gradient-to-br from-VITROWN_BLUE to-[#14213d]">
+            <div className="absolute inset-0 bg-gradient-to-t from-black/30 to-transparent" />
           </div>
-          <div className="flex flex-col items-center justify-center gap-2 pt-2 lg:pt-0">
+          <div className="flex items-end gap-6 px-2 -mt-16 relative z-10">
+            <div className="w-[130px] h-[130px] rounded-[28px] border-[5px] border-WHITE shadow-md overflow-hidden bg-WHITE3 shrink-0">
+              {seller?.storeLogo ? (
+                <img
+                  src={seller.storeLogo}
+                  alt={seller?.storeName || "store"}
+                  className="w-full h-full object-cover"
+                />
+              ) : null}
+            </div>
+            <div className="flex-1 pb-2">
+              <h1 className="flex items-center gap-2 text-[28px] font-extrabold">
+                {seller?.storeName}
+                {seller?.isVerified ? (
+                  <BadgeCheck className="text-BLUE" size={22} />
+                ) : null}
+              </h1>
+              {seller?.username ? (
+                <p className="text-GRAY text-sm mt-0.5 mb-3" dir="ltr">
+                  @{seller.username}
+                </p>
+              ) : (
+                <div className="mb-3" />
+              )}
+              <div className="flex gap-8">
+                <div>
+                  <b className="block text-[20px] font-extrabold">
+                    {seller?.productCount ?? 0}
+                  </b>
+                  <span className="text-GRAY text-[13px]">محصول</span>
+                </div>
+                <div>
+                  <b className="block text-[20px] font-extrabold">
+                    {seller?.followerCount ?? 0}
+                  </b>
+                  <span className="text-GRAY text-[13px]">دنبال‌کننده</span>
+                </div>
+                <div>
+                  <b className="flex items-center gap-1 text-[20px] font-extrabold">
+                    {seller?.productReviewsCount ? seller?.reviewAverage : "—"}
+                    {seller?.productReviewsCount ? (
+                      <Star size={16} className="fill-BLACK" />
+                    ) : null}
+                  </b>
+                  <span className="text-GRAY text-[13px]">امتیاز فروشگاه</span>
+                </div>
+              </div>
+            </div>
+            <div className="flex gap-2.5 pb-2">
+              <Button
+                variant="dark"
+                size="lg"
+                onClick={handleFollowToggle}
+                disabled={isFollowMutating || isFollowStatusLoading}
+              >
+                {isFollowed ? (
+                  <>
+                    <Check size={20} />
+                    دنبال شده
+                  </>
+                ) : (
+                  <>
+                    <UserPlus size={20} />
+                    دنبال کردن
+                  </>
+                )}
+              </Button>
+              <Button
+                variant="outline"
+                size="lg"
+                onClick={handleCreateChatThread}
+                disabled={!seller?.id || isCreatingChatThread}
+              >
+                {isCreatingChatThread ? "در حال اتصال..." : "ارسال پیام"}
+              </Button>
+            </div>
+          </div>
+          {seller?.storeDescription ? (
+            <p className="text-BLACK2 text-[14.5px] leading-8 max-w-[760px] mt-5 px-2">
+              {seller.storeDescription}
+            </p>
+          ) : null}
+          <div className="border-b border-WHITE3 mt-6" />
+        </div>
+
+        {/* Mobile header */}
+        <div className="relative lg:hidden">
+          <HeaderWithSupport
+            title={seller?.storeName || ""}
+            onBack={handleBack}
+          />
+          <div className="flex flex-col items-center justify-center gap-2 pt-2">
             <SellerLogo src={seller?.storeLogo} alt="store logo" />
-            <h1 className="hidden lg:block text-[26px] font-extrabold mt-1">
-              {seller?.storeName}
-            </h1>
           </div>
         </div>
 
         <div className="w-full">
-          <div className="w-full p-4 lg:max-w-2xl lg:mx-auto">
-            <div className="flex px-4 border bg-WHITE3 rounded-[10px] w-full py-2 lg:py-4">
+          <div className="w-full p-4 lg:hidden">
+            <div className="flex px-4 border bg-WHITE3 rounded-[10px] w-full py-2">
               <div className="w-full border-l flex-2 flex flex-col items-center justify-center">
                 <p className="text-R12">{seller?.followerCount}</p>
                 <p className="text-R12">دنبال کننده</p>
@@ -248,14 +334,14 @@ export default function Seller() {
               </div>
             </div>
           </div>
-          <div className="mt-6 px-4 lg:max-w-2xl lg:mx-auto lg:text-center">
+          <div className="mt-6 px-4 lg:hidden">
             <ReadMoreText
               sellerData={seller}
               text={seller?.storeDescription || ""}
               maxLength={150}
             />
           </div>
-          <div className="mt-4 px-4 w-full flex py-4 gap-4 lg:max-w-2xl lg:mx-auto">
+          <div className="mt-4 px-4 w-full flex py-4 gap-4 lg:hidden">
             <Button
               variant="dark"
               size="lg"
@@ -287,14 +373,17 @@ export default function Seller() {
               {isCreatingChatThread ? "در حال اتصال..." : "ارسال پیام"}
             </Button>
           </div>
-          {/* Search Bar */}
-          <SearchTopBar
-            searchValue={searchValue}
-            setSearchValue={setSearchValue}
-            placeholder="جستجو در محصولات فروشگاه..."
-            minimumPrice={0}
-            maximumPrice={10000000}
-          />
+          {/* Search Bar (mobile) */}
+          <div className="lg:hidden">
+            <SearchTopBar
+              searchValue={searchValue}
+              setSearchValue={setSearchValue}
+              placeholder="جستجو در محصولات فروشگاه..."
+              minimumPrice={0}
+              maximumPrice={10000000}
+            />
+          </div>
+          <div className="hidden lg:block lg:mt-2" />
 
           {/* seller products */}
           <MondrianProductList