diff --git a/web/editor.css b/web/editor.css
index d0fd651a2..daabd6beb 100644
--- a/web/editor.css
+++ b/web/editor.css
@@ -3,6 +3,9 @@
     background: #fff;
     color: #000;
     padding: 5px;
+    width: 100%;
+    display: inline-block;
+    box-sizing: border-box;
 }
 
 /* prevent floated images from being displayed outside field */