observe additional isabelle-jedit.css for component and user;
visial separation of message divs;

--- a/lib/html/isabelle.css	Fri May 21 15:29:20 2010 +0200
+++ b/lib/html/isabelle.css	Fri May 21 16:40:25 2010 +0200
@@ -1,4 +1,4 @@
-/* css style file for Isabelle XHTML/XML output */
+/* style file for Isabelle XHTML/XML output */
 
 body { background-color: #FFFFFF; }
 

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Tools/jEdit/dist-template/etc/isabelle-jedit.css	Fri May 21 16:40:25 2010 +0200
@@ -0,0 +1,4 @@
+/* additional style file for Isabelle/jEdit output */
+
+pre.message { margin-top: 0.3ex; background-color: #F0F0F0; }
+

--- a/src/Tools/jEdit/src/jedit/html_panel.scala	Fri May 21 15:29:20 2010 +0200
+++ b/src/Tools/jEdit/src/jedit/html_panel.scala	Fri May 21 16:40:25 2010 +0200
@@ -93,7 +93,9 @@
 <style media="all" type="text/css">
 """ +
   system.try_read("$ISABELLE_HOME/lib/html/isabelle.css") + "\n" +
-  system.try_read("$ISABELLE_HOME_USER/etc/isabelle.css") + "\n"
+  system.try_read("$JEDIT_HOME/etc/isabelle-jedit.css") + "\n" +
+  system.try_read("$ISABELLE_HOME_USER/etc/isabelle.css") + "\n" +
+  system.try_read("$ISABELLE_HOME_USER/etc/isabelle-jedit.css") + "\n"
 
   private val template_tail =
 """
@@ -152,7 +154,7 @@
       val html_body =
         current_body.flatMap(div =>
           Pretty.formatted(List(div), current_margin, Pretty.font_metric(current_font_metrics))
-            .map(t => XML.elem(HTML.PRE, HTML.spans(t))))
+            .map(t => XML.Elem(HTML.PRE, List((Markup.CLASS, Markup.MESSAGE)), HTML.spans(t))))
       val doc =
         builder.parse(
           new InputSourceImpl(new StringReader(template(current_font_size)), "http://localhost"))