diff --git a/src/platform/StackedRouter.css b/src/platform/StackedRouter.css
index 714893c..5dae005 100644
--- a/src/platform/StackedRouter.css
+++ b/src/platform/StackedRouter.css
@@ -21,6 +21,7 @@ dialog.StackedPage {
   contain-intrinsic-size: auto 560px auto 100dvh;
   content-visibility: auto;
 
+  background: var(--tutu-color-surface);
   box-shadow: var(--tutu-shadow-e16);
 
   @media (min-width: 560px) {