diff --git a/src/components/Folder/index.tsx b/src/components/Folder/index.tsx
index 12f3c353b..e9483b8df 100644
--- a/src/components/Folder/index.tsx
+++ b/src/components/Folder/index.tsx
@@ -683,7 +683,7 @@ export default function Folder({ data: _data }: { data?: Agent }) {
className={`min-h-0 flex-1 ${selectedFile?.type === 'html' && !isShowSourceCode ? 'overflow-hidden' : 'scrollbar overflow-y-auto'}`}
>
{selectedFile ? (
!loading ? (
diff --git a/src/lib/htmlFontStyles.ts b/src/lib/htmlFontStyles.ts
index 42ede91ed..40ce1cd6d 100644
--- a/src/lib/htmlFontStyles.ts
+++ b/src/lib/htmlFontStyles.ts
@@ -13,8 +13,21 @@
// ========= Copyright 2025-2026 @ Eigent.ai All Rights Reserved. =========
/**
- * Consistent font style tag for HTML content rendering.
- * Uses system fonts with !important to override inline styles.
+ * Scoped font style for HTML fragments rendered in the main document (e.g. CSV in FolderComponent).
+ * Uses a wrapper class so styles do not leak to the rest of the app (sidebar, file list, etc.).
+ */
+const SCOPED_FONT_STYLE = ``;
+
+/**
+ * Unscoped font style for full HTML documents rendered in an iframe (e.g. HtmlRenderer).
+ * Safe there because the iframe has its own document.
*/
export const FONT_STYLE_TAG = `