Topic: Is it possible styling with css?

I am producing XML file like this and  showing it on log_view.erb, but the XML  file is not colorized and formatted. how can I do it? Or is it possible?

the output like this : <OTA_ReadRQ xmlns="http://xmlvenditews.tours.com"> <ns1:OTA_ReadRQ ReturnListIndicator="true" PrimaryLangID="en" Version="1.0" xmlns:ns1="http://www.opentravel.org/OTA/2003/05" > <ns1:UniID Type="14" ID="22212"/> </ns1:OTA_ReadRQ> </OTA_ReadRQ>
 
----- show_logs ------

<div id="logs">
<% @logs.each do |log| -%>
<%= log.operation -%>:
<%= log.description -%> -
by <%= log.author.name -%> -
<%= log.created_at.strftime('%Y/%m/%d %H:%M:%S') %>
<% if log.request_data -%>
&nbsp;<%= link_to 'Request_XML', {:action => :log_view, :id => log.id, :type => 'req'}, :target => '_blank' %>
<% end -%>
<% if log.response_data -%>
&nbsp;<%= link_to 'Response_XML', {:action => :log_view, :id => log.id, :type => 'res'}, :target => '_blank' %>
<% end -%>
<hr/>
<% end -%>
</div>

------log_controller -------
def log_view
    logrecord = OperationLog.find(params[:id])
    case params[:type]
    when 'req'
      @doc = logrecord.request_data
    when 'res'
      @doc = logrecord.response_data
    end
    render :layout => false
#     render :xml  => @doc
  end

------log_view.erb-----
<h1>View logs</h1>
<textarea readonly rows="60" cols="90">
<%=h @doc %>
</textarea>