diff --git a/src/canvas-host/a2ui/index.html b/src/canvas-host/a2ui/index.html
index 25b4619a5..cd1203841 100644
--- a/src/canvas-host/a2ui/index.html
+++ b/src/canvas-host/a2ui/index.html
@@ -84,9 +84,10 @@
         inset: 0;
         display: none;
         align-items: center;
-        justify-content: flex-start;
+        justify-content: center;
         flex-direction: column;
-        padding-top: calc(20px + env(safe-area-inset-top, 0px));
+        padding: 24px;
+        box-sizing: border-box;
         pointer-events: none;
         z-index: 3;
       }