Minor simplification.
diff --git a/Doc/html/style.css b/Doc/html/style.css
index 075fdb3..7bfa16f 100644
--- a/Doc/html/style.css
+++ b/Doc/html/style.css
@@ -63,8 +63,7 @@
 .url                    { font-family: avantgarde, sans-serif }
 .file                   { font-family: avantgarde, sans-serif }
 
-.tableheader td         { background-color: #99ccff; }
-.tableheader th         { background-color: #99ccff;
+.tableheader            { background-color: #99ccff;
                           font-family: avantgarde, sans-serif; }
 
 .refcount-info          { font-style: italic }