diff --git a/media/css/main.css b/media/css/main.css
index 3be226d3..28e01b8d 100644
--- a/media/css/main.css
+++ b/media/css/main.css
@@ -1851,6 +1851,14 @@ details.release-notes-list {
     max-width: 650px;
 }
 
+.moderation-preview-iframe {
+    width: 100%;
+    min-height: 400px;
+    border: 1px solid var(--button-input-bdr-color);
+    border-radius: 5px;
+    background-color: #fff;
+}
+
 /* Buttons that are images */
 button.imagebutton {
     border: 0;
diff --git a/media/js/moderation_preview.js b/media/js/moderation_preview.js
new file mode 100644
index 00000000..a6634463
--- /dev/null
+++ b/media/js/moderation_preview.js
@@ -0,0 +1,33 @@
+/*
+ * Moderation preview handler
+ * Renders HTML content in iframes to isolate styles from the main page
+ */
+document.addEventListener('DOMContentLoaded', function() {
+    /* Find preview data textareas and render them in iframes */
+    var dataAreas = document.getElementsByClassName('moderation-preview-data');
+    for (var i = 0; i < dataAreas.length; i++) {
+        var dataArea = dataAreas[i];
+        var container = dataArea.parentElement;
+        var content = dataArea.value;
+
+        /* Create an iframe to isolate the HTML content styles */
+        var iframe = document.createElement('iframe');
+        iframe.className = 'moderation-preview-iframe';
+        iframe.sandbox = 'allow-same-origin';
+        iframe.srcdoc = content;
+
+        /* Resize iframe to fit content after it loads */
+        iframe.onload = function() {
+            try {
+                var contentHeight = this.contentDocument.body.scrollHeight;
+                if (contentHeight > 0) {
+                    this.style.height = (contentHeight + 20) + 'px';
+                }
+            } catch (e) {
+                /* Ignore cross-origin errors */
+            }
+        };
+
+        container.appendChild(iframe);
+    }
+});
diff --git a/templates/account/submit_preview.html b/templates/account/submit_preview.html
index 054e03bf..c7ac5a6e 100644
--- a/templates/account/submit_preview.html
+++ b/templates/account/submit_preview.html
@@ -17,7 +17,16 @@
 {%for fld, title, contents, mdcontents, note in preview %}
 <div class="row">
   <div class="col-sm-2 col-form-label"><strong>{{title}}</strong></div>
-  <div class="col-sm-10">{%if mdcontents%}<div class="moderation-mdpreview-wrap">{{mdcontents|safe}}</div>{%else%}{{contents}}{%endif%}</div>
+  <div class="col-sm-10">
+    {%if mdcontents%}
+      <div class="moderation-mdpreview-wrap moderation-preview-container">
+        {# Use hidden textarea to store raw HTML without browser parsing #}
+        <textarea class="moderation-preview-data" style="display:none;">{{mdcontents}}</textarea>
+      </div>
+    {%else%}
+      {{contents}}
+    {%endif%}
+  </div>
 </div>
 {%endfor%}
 
@@ -25,3 +34,7 @@
 {%include "base/form_contents.html" with savebutton="Submit for moderation"%}
 
 {%endblock%}
+
+{%block extrascript%}
+<script src="/media/js/moderation_preview.js?{{gitrev}}"></script>
+{%endblock%}