diff --git a/theme/textalternativeform.css b/theme/textalternativeform.css
index 37f86194..9cda2370 100644
--- a/theme/textalternativeform.css
+++ b/theme/textalternativeform.css
@@ -3,7 +3,13 @@
  * For licensing, see LICENSE.md.
  */
 
+@import "@ckeditor/ckeditor5-theme-lark/theme/mixins/_rwd.css";
+
 .ck.ck-text-alternative-form {
+	display: flex;
+	flex-direction: row;
+	flex-wrap: nowrap;
+
 	& .ck-labeled-input {
 		display: inline-block;
 	}
@@ -11,4 +17,16 @@
 	& .ck-label {
 		display: none;
 	}
+
+	@mixin ck-media-phone {
+		flex-wrap: wrap;
+
+		& .ck-labeled-input {
+			flex-basis: 100%;
+		}
+
+		& .ck-button {
+			flex-basis: 50%;
+		}
+	}
 }