diff --git a/editions/tw5.com/tiddlers/system/tw5.com-styles.tid b/editions/tw5.com/tiddlers/system/tw5.com-styles.tid
index ced42e64d..68944098d 100644
--- a/editions/tw5.com/tiddlers/system/tw5.com-styles.tid
+++ b/editions/tw5.com/tiddlers/system/tw5.com-styles.tid
@@ -133,3 +133,15 @@ type: text/vnd.tiddlywiki
 .tc-saving-sidebar-category { margin-bottom:10px; }
 .tc-saving-sidebar-category-title { margin-bottom:5px; font-weight:bold; }
 .tc-saving-sidebar-category-item { margin-left:10px; white-space:nowrap; }
+
+.tc-scary-warning {
+	font-weight: bold;
+	padding: 0 1em;
+	margin-left: -1em;
+	margin-right: -1em;
+	color: #f22;
+	border-radius: 4px;
+	border: 3px solid transparent;
+	background: #ffd;
+	background: linear-gradient(#ffd, #ffd) padding-box, repeating-linear-gradient(-45deg, red 0, red 25%, transparent 0, transparent 50%) 0 / .6em .6em;
+}