Fix issue #271: "BOM" looking ugly on light mode

Change the background-color to different color.

Author: JanPoonthong

website/public/errors/index.ejs.html

@@ -49,11 +49,17 @@
 
       .unicode-bom:before {
         content: "BOM";
+        background-color: #edbf66;
         border: 1px solid red;
-        background-color: #884444;
         border-radius: 5px;
         padding: 1px 3px;
       }
+
+      @media (prefers-color-scheme: dark) {
+        .unicode-bom:before {
+          background-color: #884444;
+        }
+      }
     </style>
   </head>