From 79ba9b381876893c700556d5f522db72cfa6b79d Mon Sep 17 00:00:00 2001
From: Huang Xin <chrox.huang@gmail.com>
Date: Tue, 24 Feb 2026 22:18:12 +0800
Subject: [PATCH] compat(css): unset font-family for body when set to serif or
 sans-serif, closes #3334 (#3363)

---
 apps/readest-app/src/utils/style.ts | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/apps/readest-app/src/utils/style.ts b/apps/readest-app/src/utils/style.ts
index d9ea2758..786e5828 100644
--- a/apps/readest-app/src/utils/style.ts
+++ b/apps/readest-app/src/utils/style.ts
@@ -737,6 +737,21 @@ export const transformStylesheet = (css: string, vw: number, vh: number, vertica
     return selector + block;
   });
 
+  // unset font-family for body when set to serif or sans-serif
+  css = css.replace(ruleRegex, (_, selector, block) => {
+    if (/\bbody\b/i.test(selector)) {
+      const hasSerifFont = /font-family\s*:\s*serif\s*[;$]/.test(block);
+      const hasSansSerifFont = /font-family\s*:\s*sans-serif\s*[;$]/.test(block);
+      if (hasSerifFont) {
+        block = block.replace(/font-family\s*:\s*serif\s*([;$])/gi, 'font-family: unset$1');
+      }
+      if (hasSansSerifFont) {
+        block = block.replace(/font-family\s*:\s*sans-serif\s*([;$])/gi, 'font-family: unset$1');
+      }
+    }
+    return selector + block;
+  });
+
   // replace absolute font sizes with rem units
   // replace vw and vh as they cause problems with layout
   // replace hardcoded colors