From 130fa4c94f41880fc17cda27e1878e28ddfdd65c Mon Sep 17 00:00:00 2001
From: Wulian233 <1055917385@qq.com>
Date: Fri, 14 Mar 2025 20:27:13 +0800
Subject: [PATCH] [3.13] gh-131204: Fix `difflib.HtmlDiff` may not use
 monospaced font (GH-131221) (#131242)

(cherry picked from commit 7fd6160)
---
 Lib/difflib.py                                                  | 2 +-
 Lib/test/test_difflib_expect.html                               | 2 +-
 .../next/Library/2025-03-14-09-28-13.gh-issue-131204.wogNEX.rst | 1 +
 3 files changed, 3 insertions(+), 2 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Library/2025-03-14-09-28-13.gh-issue-131204.wogNEX.rst

diff --git a/Lib/difflib.py b/Lib/difflib.py
index ba0b256969eb..33e7e6c165aa 100644
--- a/Lib/difflib.py
+++ b/Lib/difflib.py
@@ -1628,7 +1628,7 @@ def _line_pair_iterator():
 </html>"""
 
 _styles = """
-        table.diff {font-family:Courier; border:medium;}
+        table.diff {font-family: Menlo, Consolas, Monaco, Liberation Mono, Lucida Console, monospace; border:medium}
         .diff_header {background-color:#e0e0e0}
         td.diff_header {text-align:right}
         .diff_next {background-color:#c0c0c0}
diff --git a/Lib/test/test_difflib_expect.html b/Lib/test/test_difflib_expect.html
index 3e6a7b7a9933..12091206a285 100644
--- a/Lib/test/test_difflib_expect.html
+++ b/Lib/test/test_difflib_expect.html
@@ -9,7 +9,7 @@
           content="text/html; charset=utf-8" />
     <title></title>
     <style type="text/css">
-        table.diff {font-family:Courier; border:medium;}
+        table.diff {font-family: Menlo, Consolas, Monaco, Liberation Mono, Lucida Console, monospace; border:medium}
         .diff_header {background-color:#e0e0e0}
         td.diff_header {text-align:right}
         .diff_next {background-color:#c0c0c0}
diff --git a/Misc/NEWS.d/next/Library/2025-03-14-09-28-13.gh-issue-131204.wogNEX.rst b/Misc/NEWS.d/next/Library/2025-03-14-09-28-13.gh-issue-131204.wogNEX.rst
new file mode 100644
index 000000000000..e821e61a0ca5
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-03-14-09-28-13.gh-issue-131204.wogNEX.rst
@@ -0,0 +1 @@
+Use monospace font from System Font Stack for cross-platform support in  :class:`difflib.HtmlDiff`.