diff --git a/css/chat.js b/css/chat.js
index 4a78e454fc..cbdcf91e92 100644
--- a/css/chat.js
+++ b/css/chat.js
@@ -1,2 +1,6 @@
-document.getElementById("main").childNodes[0].style = "max-width: 800px; margin-left: auto; margin-right: auto";
-document.getElementById("extensions").style = "max-width: 800px; margin-left: auto; margin-right: auto";
+document.getElementById("main").style.setProperty("max-width", "800px");
+document.getElementById("main").style.setProperty("margin-left", "auto");
+document.getElementById("main").style.setProperty("margin-right", "auto");
+document.getElementById("extensions").style.setProperty("max-width", "800px");
+document.getElementById("extensions").style.setProperty("margin-left", "auto");
+document.getElementById("extensions").style.setProperty("margin-right", "auto");