diff --git a/src/platform/StackedRouter.css b/src/platform/StackedRouter.css
index eac26ce..a946a2d 100644
--- a/src/platform/StackedRouter.css
+++ b/src/platform/StackedRouter.css
@@ -15,6 +15,16 @@ dialog.StackedPage {
   width: 560px;
   max-height: 100vh;
   max-height: 100dvh;
+  /*
+  * WebKit does not see contain-instric-size as the real element size.
+  * If the container does not have height, the child element using 100%
+  * height (usually Scafflod in our case) was have 0px computed height.
+  *
+  * This behaviour is different from Firefox. So we need to actually
+  * define the box height here. (Rubicon)
+  */
+  height: 100vh;
+  height: 100dvh;
   background: none;
   display: none;
 
@@ -31,10 +41,9 @@ dialog.StackedPage {
 
   @media (max-width: 560px) {
     & {
+      margin: 0;
       width: 100vw;
       width: 100dvw;
-      height: 100vh;
-      height: 100dvh;
       contain-intrinsic-size: 100vw 100vh;
       contain-intrinsic-size: 100dvw 100dvh;
     }