diff --git a/public/404.html b/public/404.html
index a1d7e970fd0..fe293183e36 100644
--- a/public/404.html
+++ b/public/404.html
@@ -4,9 +4,9 @@
   <meta charset="utf-8" />
   <title>Redmine 404 error</title>
   <style>
-    body {font-family: "Trebuchet MS", Georgia, "Times New Roman", serif; color: #303030; margin: 10px;}
-    h1 {font-size:1.5em;}
-    p {font-size:0.8em;}
+    body {font-family: sans-serif; color: #303030; margin: 20px; line-height: 1.6;}
+    h1 {font-size: 1.5rem;}
+    p {font-size: 0.875rem;}
   </style>
 </head>
 <body>
diff --git a/public/500.html b/public/500.html
index 254e20df272..91b804a7c92 100644
--- a/public/500.html
+++ b/public/500.html
@@ -4,9 +4,9 @@
   <meta charset="utf-8" />
   <title>Redmine 500 error</title>
   <style>
-    body {font-family: "Trebuchet MS", Georgia, "Times New Roman", serif; color: #303030; margin: 10px;}
-    h1 {font-size:1.5em;}
-    p {font-size:0.8em;}
+    body {font-family: sans-serif; color: #303030; margin: 20px; line-height: 1.6;}
+    h1 {font-size: 1.5rem;}
+    p {font-size: 0.875rem;}
   </style>
 </head>
 <body>
