Improve Catalogs page layout with spacing and styling

Added CSS classes for better spacing between form and grid.
Wrapped form in .action-panel and grid in .grid-section divs
to enhance visual separation. No functional changes made.

DbFirst.BlazorWasm/Pages/Catalogs.razor

@@ -1,6 +1,11 @@
 @page "/catalogs"
 @inject CatalogApiClient Api
 
+<style>
+    .action-panel { margin-bottom: 16px; }
+    .grid-section { margin-top: 12px; }
+</style>
+
 <PageTitle>Catalogs</PageTitle>
 
 <h1>Catalogs</h1>
@@ -20,6 +25,7 @@ else if (!string.IsNullOrWhiteSpace(infoMessage))
 
 @if (showForm)
 {
+    <div class="action-panel">
         <EditForm Model="formModel" OnValidSubmit="HandleSubmit" Context="editCtx">
             <DxFormLayout ColCount="2">
                 <DxFormLayoutItem Caption="Titel" Context="itemCtx">
@@ -45,6 +51,7 @@ else if (!string.IsNullOrWhiteSpace(infoMessage))
                 </DxFormLayoutItem>
             </DxFormLayout>
         </EditForm>
+    </div>
 }
 
 @if (isLoading)
@@ -57,6 +64,7 @@ else if (items.Count == 0)
 }
 else
 {
+    <div class="grid-section">
         <DxGrid Data="@items" TItem="CatalogReadDto" KeyFieldName="@nameof(CatalogReadDto.Guid)" ShowFilterRow="true" PageSize="10" CssClass="mb-4">
             <Columns>
                 <DxGridDataColumn FieldName="@nameof(CatalogReadDto.Guid)" Caption="Id" Width="140px" />
@@ -77,6 +85,7 @@ else
                 </DxGridDataColumn>
             </Columns>
         </DxGrid>
+    </div>
 }
 
 @code {