diff --git a/components/style/themes/default.less b/components/style/themes/default.less
index 142adde6ff..d96ac83a2b 100644
--- a/components/style/themes/default.less
+++ b/components/style/themes/default.less
@@ -275,11 +275,13 @@
 @radio-wrapper-margin-right: 8px;
 
 // Media queries breakpoints
-// Extra small screen / phone
+// @screen-xs and @screen-xs-min is not used in Grid
+// smallest break point is @screen-md
 @screen-xs: 480px;
 @screen-xs-min: @screen-xs;
+// 👆 Extra small screen / phone
 
-// Small screen / tablet
+// 👇 Small screen / tablet
 @screen-sm: 576px;
 @screen-sm-min: @screen-sm;