html and css structure fix

static/custom.css

@@ -7,6 +7,10 @@ table.sortable th:not(.sorttable_sorted):not(.sorttable_sorted_reverse):not(.sor
     content: " \25B4\25BE"
 }
 
+.obsolete{
+    filter: saturate(2.5) brightness(.85);
+    border-left: 4px solid #d50000;  
+}
 
 .custom-toc-1 {
  border-left-color:#f2f2f2;