diff --git a/src/styles/base.sass b/src/styles/base.sass
index 2d2ff850..06923efd 100644
--- a/src/styles/base.sass
+++ b/src/styles/base.sass
@@ -49,6 +49,9 @@ strong, b
 			left: 0
 			right: 0
 
+	&.box
+		+container-box
+
 .container-page
 	background-color: $color-background