style(store): improve styling of store

src/interface/components/store/Backgrounds.svelte

@@ -210,7 +210,7 @@
   <!-- Main Content -->
   <div class="flex-1 overflow-auto">
     <!-- Header -->
-    <div class="sticky top-0 z-10 p-4 bg-white border-b dark:bg-zinc-900 dark:border-zinc-700">
+    <div class="sticky top-0 z-10 p-4 border-b bg-[#F1F1F3] dark:bg-zinc-900 dark:border-zinc-700">
       <div class="flex items-center justify-between mb-4">
         <h1 class="text-2xl font-bold">Explore Backgrounds {searchTerm ? `- "${searchTerm}"` : ''}</h1>
         <div class="flex items-center gap-4">
@@ -219,7 +219,6 @@
             class="p-2 border rounded-lg border-zinc-200 dark:border-zinc-700 dark:bg-zinc-800"
           >
             <option value="newest">Newest</option>
-            <option value="popular">Most Popular</option>
             <option value="name">Name</option>
           </select>
         </div>

src/interface/pages/store.svelte

@@ -98,7 +98,7 @@
   <div class="h-full overflow-y-scroll bg-zinc-200/50 dark:bg-zinc-900 dark:text-white pt-[4.25rem]">
     <Header {searchTerm} {setSearchTerm} {darkMode} {activeTab} {setActiveTab} />
     
-    <div class={`px-12 h-full ${activeTab === 'backgrounds' ? 'pt-0' : 'pt-6'}`}>
+    <div class={`px-12 h-full ${activeTab === 'backgrounds' ? 'pt-0' : 'pt-6 md:px-24 lg:px-48'}`}>
       <!-- Loading State -->
       {#if loading}
         <div class="grid grid-cols-1 gap-4 py-12 mx-auto sm:grid-cols-2 lg:grid-cols-3">