1 files changed, 21 insertions, 0 deletions
diff --git a/layout/style/res/html.css b/layout/style/res/html.css
index bc3f08210..1f572467f 100644
--- a/layout/style/res/html.css
+++ b/layout/style/res/html.css
@@ -799,6 +799,27 @@ input[type="date"] > xul|datetimebox {
   }
 }
 
+/* <dialog> element styles */
+
+dialog {
+  position: absolute;
+  offset-inline-start: 0;
+  offset-inline-end: 0;
+  color: black;
+  margin: auto;
+  border-width: initial;
+  border-style: solid;
+  border-color: initial;
+  border-image: initial;
+  padding: 1em;
+  background: white;
+  width: -moz-fit-content;
+}
+
+dialog:not([open]) {
+  display: none;
+}
+
 /* emulation of non-standard HTML <marquee> tag */
 marquee {
   inline-size: -moz-available;