update background color for pre

Signed-off-by: Victor Chang <[email protected]>

Author: mocsharp

docs/templates/material/styles/main.css

@@ -298,7 +298,7 @@ pre {
     font-size: 13px;
     word-break: break-all;
     word-wrap: break-word;
-    background-color: #fffaef;
+    background-color: #eef9f9;
     border-radius: 4px;
     border: none;
     box-shadow: var(--card-box-shadow);