Clarify card group behavior (#30416)

Co-authored-by: Mark Otto <markd.otto@gmail.com>

diff --git a/site/content/docs/4.3/components/card.md b/site/content/docs/4.3/components/card.md
index 5fd1fce4591a05d587bbb772d3ea6c89a3a0775b..4bb116f0f9f48e4eb0536db2d522818774ca7ae1 100644 (file)
--- a/site/content/docs/4.3/components/card.md
+++ b/site/content/docs/4.3/components/card.md
@@ -463,7 +463,7 @@ In addition to styling the content within cards, Bootstrap includes a few option
 
 ### Card groups
 
-Use card groups to render cards as a single, attached element with equal width and height columns. Card groups use `display: flex;` to achieve their uniform sizing.
+Use card groups to render cards as a single, attached element with equal width and height columns. Card groups start off stacked and use `display: flex;` to become attached with uniform dimensions starting at the `sm` breakpoint.
 
 {{< example >}}
 <div class="card-group">