diff --git a/newspack-theme/sass/style-editor-overrides.scss b/newspack-theme/sass/style-editor-overrides.scss
index 225382c7c..bbb428b9f 100644
--- a/newspack-theme/sass/style-editor-overrides.scss
+++ b/newspack-theme/sass/style-editor-overrides.scss
@@ -12,10 +12,11 @@
 /** === Default Template === */
 
 @include media( mobile ) {
-	body.newspack-default-template .wp-block[data-align='full'] {
+	body.newspack-default-template
+		.block-editor-block-list__layout.is-root-container
+		> .wp-block[data-align='full'] {
 		margin-left: auto;
 		margin-right: auto;
-		max-width: 780px;
 	}
 }