fix nextjs bug

Author: YousefED

packages/core/src/editor.module.css

@@ -36,7 +36,7 @@ Tippy popups that are appended to document.body directly
 .defaultStyles h2,
 .defaultStyles h3,
 .defaultStyles li {
-  all: unset;
+  all: unset !important;
   margin: 0;
   padding: 0;
   font-size: inherit;

packages/react/src/utils.ts

@@ -1,7 +1,8 @@
 export const isAppleOS = () =>
-  /Mac/.test(navigator.platform) ||
-  (/AppleWebKit/.test(navigator.userAgent) &&
-    /Mobile\/\w+/.test(navigator.userAgent));
+  typeof navigator !== "undefined" &&
+  (/Mac/.test(navigator.platform) ||
+    (/AppleWebKit/.test(navigator.userAgent) &&
+      /Mobile\/\w+/.test(navigator.userAgent)));
 
 export function formatKeyboardShortcut(shortcut: string) {
   if (isAppleOS()) {