Refactor WalletPage layout for improved responsiveness and user experience

- Updated the layout of WalletPage to use a flex column for better alignment on smaller screens.
- Adjusted button styles to ensure consistent sizing and spacing across different screen sizes.
- Enhanced the overall structure for a more organized presentation of wallet information.

These changes improve the usability of the WalletPage, making it more accessible on various devices.

src/modules/wallet/views/WalletPage.vue

@@ -118,16 +118,16 @@ onMounted(() => {
         <CardDescription>Available across all your wallets</CardDescription>
       </CardHeader>
       <CardContent>
-        <div class="flex items-center justify-between">
+        <div class="flex flex-col sm:flex-row items-start sm:items-center justify-between gap-4">
           <div class="text-3xl font-bold">
             <CurrencyDisplay :balance-msat="totalBalance" />
           </div>
 
-          <div class="flex gap-2">
+          <div class="flex gap-2 w-full sm:w-auto">
             <Button
               variant="default"
               @click="showReceiveDialog = true"
-              class="gap-2"
+              class="gap-2 flex-1 sm:flex-none"
             >
               <QrCode class="h-4 w-4" />
               Receive
@@ -135,7 +135,7 @@ onMounted(() => {
             <Button
               variant="outline"
               @click="showSendDialog = true"
-              class="gap-2"
+              class="gap-2 flex-1 sm:flex-none"
             >
               <Send class="h-4 w-4" />
               Send