diff --git a/frontend/src/styles/globals.css b/frontend/src/styles/globals.css
index 4abb0691..739e9c70 100644
--- a/frontend/src/styles/globals.css
+++ b/frontend/src/styles/globals.css
@@ -411,6 +411,12 @@
   --container-width-lg: calc(var(--spacing) * 256);
 }
 
+html,
+body {
+  font-family: "Microsoft YaHei", "微软雅黑", "PingFang SC", ui-sans-serif,
+    system-ui, sans-serif;
+}
+
 /* ========================================
    Streamdown Markdown Styles
    使用 data-streamdown 属性选择器统一定义
@@ -452,9 +458,9 @@ pre {
   font-size: calc(16px * var(--zoom-scale));
 }
 
-/* 二三级标题 - 16px */
+/* 代码块 - 14px */
 [data-streamdown="code-block"] pre {
-  font-size: calc(16px * var(--zoom-scale));
+  font-size: calc(14px * var(--zoom-scale));
 }
 
 .cm-line {