fix CSS class "data2" when nested tables

sonar-server/src/main/webapp/WEB-INF/app/views/rules_configuration/_rule.html.erb

               <% end %>
           </table>
       <% end %>
-      <br/><span class="gray">Key: <%= rule.plugin_rule_key -%></span>
+      <br/><span>Key: <%= rule.plugin_rule_key -%></span>
       <% if is_admin %>
         <br/>
         <% if rule.template? %>

sonar-server/src/main/webapp/stylesheets/style.css

 }
 
 .rule_desc {
-  color: #333;
+  color: #444;
   padding: 2px 0 15px 0;
 }
 
 table.without-header {
   border-top: 1px solid #ddd;
 }
-table.data2 tbody tr {
+table.data2 > tbody > tr {
   border-left: 1px solid #ddd;
   border-right: 1px solid #ddd;
 }
-table.data2 thead tr {
+table.data2 > thead > tr {
   height: 24px;
   border: 0;
 }
-table.data2 th, table.data2 td {
+table.data2 > thead > tr > th, table.data2 > tbody > tr > td {
   border-bottom: 1px solid #DDD;
-  padding: 2px 4px 2px 4px;
+  padding: 3px 5px;
   height: 24px;
   vertical-align: middle;
 }
-table.data2 td {
+table.data2 > tbody > tr > td {
   vertical-align: middle;
 }
-table.data2 th {
+table.data2 > thead > tr > th {
   font-weight: bold;
 }
-table.data2 tfoot td {
+table.data2 > tfoot > tr > td {
   border-bottom: 0;
 }
 table.data2 td, table.data2 td a, table.data2 th, table.data2 th a {
   color: #444;
 }
+table.data2 img, table.data2 input, table.data2 select {
+  vertical-align: text-bottom;
+}
 .background-gray {
   background-color: #f4f4f4;
   color: #555;