nit

frontend/src/lib/components/graph/GroupNodeCard.svelte

@@ -87,8 +87,8 @@
 <div
 	class={twMerge(
 		'w-full module cursor-pointer max-w-full',
-		fullWidth ? 'rounded-t-md' : 'rounded-md drop-shadow-base overflow-clip',
-		'bg-surface',
+		fullWidth ? 'rounded-t-md' : 'shadow-sm border rounded-md  overflow-clip',
+		'bg-surface-tertiary',
 		noteColorConfig ? noteColorConfig.text : ''
 	)}
 	style={fullWidth ? '' : 'width: 275px;'}
@@ -137,6 +137,7 @@
 			>
 		{/if}
 	</div>
+
 	{#if showNote}
 		<div class="relative z-1">
 			<GroupNoteArea

frontend/src/lib/components/graph/renderers/nodes/CollapsedGroupNode.svelte

@@ -28,6 +28,16 @@
 	{#snippet children({ darkMode })}
 		<!-- svelte-ignore a11y_no_static_element_interactions -->
 		<div class="relative" onmouseenter={() => (hover = true)} onmouseleave={() => (hover = false)}>
+			<!-- Stacked layers behind the card -->
+			<div
+				class="absolute inset-0 top-[4px] left-2 h-9 rounded-md bg-surface border border-gray-300 z-[-1]"
+				style="width: 259px;"
+			></div>
+			<div
+				class="absolute inset-0 top-[7px] left-4 h-9 rounded-md bg-[#F2F2F8] border border-gray-300 z-[-2]"
+				style="width: 243px;"
+			></div>
+
 			<GroupNodeCard
 				summary={data.summary}
 				color={data.color}