adds clarification that gris values should be set in px (#23829)

diff --git a/docs/4.0/layout/grid.md b/docs/4.0/layout/grid.md
index 3723adbe50121d5f6518671c2057d2faf7507b76..8d466aef3cf5d1b75160299bfc226f8cdad1666d 100644 (file)
--- a/docs/4.0/layout/grid.md
+++ b/docs/4.0/layout/grid.md
@@ -727,4 +727,4 @@ $container-max-widths: (
 );
 {% endhighlight %}
 
-When making any changes to the Sass variables or maps, you'll need to save your changes and recompile. Doing so will output a brand new set of predefined grid classes for column widths, offsets, and ordering. Responsive visibility utilities will also be updated to use the custom breakpoints.
+When making any changes to the Sass variables or maps, you'll need to save your changes and recompile. Doing so will output a brand new set of predefined grid classes for column widths, offsets, and ordering. Responsive visibility utilities will also be updated to use the custom breakpoints. Make sure to set grid values in `px` (not `rem`, `em` or `%`).