Pretty much works.

cms/static/css/tiny-mce.css

@@ -0,0 +1,50 @@
+body {
+    background-color: #fff;
+    font-family: 'Open Sans', Verdana, Arial, Helvetica, sans-serif;
+    font-size: 16px;
+    line-height: 1.6;
+    color: #3c3c3c;
+    scrollbar-3dlight-color: #F0F0EE;
+    scrollbar-arrow-color: #676662;
+    scrollbar-base-color: #F0F0EE;
+    scrollbar-darkshadow-color: #DDDDDD;
+    scrollbar-face-color: #E0E0DD;
+    scrollbar-highlight-color: #F0F0EE;
+    scrollbar-shadow-color: #F0F0EE;
+    scrollbar-track-color: #F5F5F5;
+}
+
+a {
+    color: #1d9dd9;
+    text-decoration: none;
+}
+
+p {
+    font-size: 16px;
+    line-height: 1.6;
+}
+
+h2 {
+    color: #646464;
+    font-size: 19px;
+    font-weight: 300;
+    letter-spacing: 1px;
+    margin-bottom: 15px;
+    text-transform: uppercase;
+}
+
+h3 {
+    font-size: 19px;
+    font-weight: 400;
+}
+
+code {
+    margin: 0 2px;
+    padding: 0px 5px;
+    border-radius: 3px;
+    border: 1px solid #eaeaea;
+    white-space: nowrap;
+    font-family: Monaco, monospace;
+    font-size: 14px;
+    background-color: #f8f8f8;
+}

cms/templates/widgets/html-edit.html

@@ -1,15 +1,13 @@
 <%include file="metadata-edit.html" />
 <section class="html-edit">
-    <div class="html-editor editor">
-        <div class="row">
-            <div class="editor-bar">
-                <ul class="editor-tabs">
-                    <li><a href="#" class="visual-tab tab current" data-tab="visual">Visual</a></li>
-                    <li><a href="#" class="html-tab tab" data-tab="html">Advanced</a></li>
-                </ul>
-            </div>
-            <textarea class="tiny-mce">${data}</textarea>
-            <div name="" class="edit-box">${data}</div>
+    <div class="row">
+        <div class="editor-bar">
+            <ul class="editor-tabs">
+                <li><a href="#" class="visual-tab tab current" data-tab="visual">Visual</a></li>
+                <li><a href="#" class="html-tab tab" data-tab="advanced">Advanced</a></li>
+            </ul>
         </div>
+        <textarea class="tiny-mce">${data}</textarea>
+        <div name="" class="edit-box">${data}</div>
     </div>
 </section>