diff --git a/docs/_sass/custom/custom.scss b/docs/_sass/custom/custom.scss
index 491b412..d1bb0e0 100644
--- a/docs/_sass/custom/custom.scss
+++ b/docs/_sass/custom/custom.scss
@@ -24,6 +24,25 @@ p.note::before, blockquote.note::before {
     padding-bottom: 0.125rem;
 }
 
+.warning {
+  background-color: rgba(247, 126, 126, 0.2);
+  border-left: 4px solid #dd2e2e;
+  padding: 0.8rem;
+  margin: 1em 0;
+  border-radius: 4px;
+  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.12), 0 3px 10px rgba(0, 0, 0, 0.08);
+}
+
+p.warning::before, blockquote.warning::before {
+  color: #dd2e2e;
+  content: "warning";
+  display: block;
+  font-weight: bold;
+  text-transform: uppercase;
+  font-size: 0.75em;
+  padding-bottom: 0.125rem;
+}
+
 span.label.label-grey {
   background-color: #ededed;
   color: #6c757d;