add main.scss

packages/editor/src/main.scss

@@ -0,0 +1,8 @@
+body {
+  min-height: 100vh;
+  margin: 0;
+}
+
+#root {
+  min-height: 100vh;
+}

packages/editor/src/main.tsx

@@ -4,6 +4,8 @@ import ReactDOM from 'react-dom/client';
 
 import { CodemirrorEditor } from './components/CodemirrorEditor';
 
+import './main.scss';
+
 const rootElem = document.getElementById('root');
 
 // eslint-disable-next-line @typescript-eslint/no-non-null-assertion