diff --git a/doc/static/acrn-custom.css b/doc/static/acrn-custom.css
index e32c804b2..539e838c0 100644
--- a/doc/static/acrn-custom.css
+++ b/doc/static/acrn-custom.css
@@ -233,6 +233,7 @@ kbd
 
 .grid-item img {
     max-width: 50%;
+    max-height: 50%;
     margin-bottom: 0.7rem;
 }