fix: background color for full screen in light mode

frontend/src/container/GridCardLayout/GridCardLayout.styles.scss

@@ -5,3 +5,8 @@
 		border: none !important;
 	}
 }
+
+.fullscreen-grid-container--light {
+	@extend .fullscreen-grid-container;
+	background-color: #f5f5f5;
+}

frontend/src/container/GridCardLayout/GridCardLayout.tsx

@@ -141,7 +141,14 @@ function GraphLayout({ onAddPanelHandler }: GraphLayoutProps): JSX.Element {
 				)}
 			</ButtonContainer>
 
-			<FullScreen handle={handle} className="fullscreen-grid-container">
+			<FullScreen
+				handle={handle}
+				className={
+					isDarkMode
+						? 'fullscreen-grid-container'
+						: 'fullscreen-grid-container--light'
+				}
+			>
 				<ReactGridLayout
 					cols={12}
 					rowHeight={100}