linea de division

[lobbys]

hola masters:
mi preg es algo simple (espero) deseo poner lineas de divsion para cada contenido o item (articulo) de un bloque hecho en css. segun pienso eso sedeeb hacerel layout pero no encuentro que esl oque debo modificar o que debo agregar.
Agradeceria meresponder este post
este es mi codigo

Código:

/***
 *** Blocks
 ***/

/*Accessibility: Skip block link, for keyboard-only users. */
a.skip-block, a.skip {
  position: absolute;
  top: -1000em;
  font-size: 0.85em;
  border-bottom: 4px;
}

a.skip-block:focus, a.skip-block:active,
a.skip:focus, a.skip:active {
  position: static;
  display: block;
}
.skip-block-to, #maincontent {
  display: none;
  height: 1px;
  border:3px;
}

.sideblock {
  border-width: 1px;
  border-style: solid;
  margin-bottom:1em;
  width: 100%;
}

.sideblock .header, .sideblock h2.header {
  text-align: center;
  margin:0;
  padding:4px;
  padding-top:3px;
  border-style: solid;
  border-width: 1px;
}
.sideblock h2 {
  margin:0;
  padding:1px;
}

.sideblock .header .hide-show-image {
  float:right;
  height:11px;
  width:11px;
  margin-top:0.25em;
}

.sideblock .header .commands {
  margin-top: 0.3em;
  clear: both;
  height: 16px;
}

.sideblock .header .commands a {
  margin: 0px 9px;
}

#left-column .hidden .header,
#right-column .hidden .header
{
  border-bottom-width: 1px ;
  border-bottom-style: solid;
}

#left-column .hidden .content,
#right-column .hidden .content
{
  display: inline;
  border: 2px;
}

.sideblock .header .icon.hide,
.sideblock .header .icon.edit {
  margin-right: 3px;
}

.sideblock .content {
  padding: 7px;
  border-width: 3px;
  border-style: solid;
}

.sideblock .content h3,
.sideblock .content h2 {
  text-align: left;
}

.sideblock .content h2 {
  margin:5em 3em 8em;
  padding:4px;
}

.sideblock .content .head {
  margin-top: 10px;
}

.sideblock .content hr {
  height:1px;
  margin-top:4px;
  margin-bottom:3px ;
  border:2px;
  border-top:1px solid;
}

.sideblock div.column {
  margin:2px;
  margin-right:4px;
  padding:3px;
}

.sideblock div.column.c0 {
  float: left;
}

.sideblock div.column.c1 {
  display: inline;
}

.sideblock .content .c0 img.icon {
  margin:5px;
}

.sideblock .content .list, .unlist, .inline-list {
  list-style:none;
  padding:5px;
  margin:2px;
}

.sideblock .content .list {
  width: 100%;
}

.sideblock .content .list li {
  clear: left;
}

.sideblock .content .inline-list li, .inline-list li {
  display: inline;
}

.sideblock .content ul.list li.listentry {
  clear:both;
}

.sideblock .content div.info {
  text-align:center;
}

.sideblock .footer {
  margin-bottom: 2px;
  text-align:center;
  clear:both;
}

.sideblock img.userpicture {
  width:10px;
  height:10px;
  margin-right:4px;
}

.blockconfigtable {
  margin-top: 3px;
  margin-right: auto;
  margin-left: auto;
  margin.bottom: 3px;
}

.blockconfigtable td.label {
  text-align: right;
  width: 50%;
}

.blockconfigtable td.value {
  text-align: left;
  width: 50%;
}

.blockconfigtable td.submit {
  text-align: center;
}

.blockconfiginstancecontent .tabs {
  margin-bottom: 2px;
  margin-left: auto;
  margin-right: auto;
}

.block_adminblock {
  width: 180px;
}

.block_messages .content {
  text-align:left;
  font-size:0.75em;
  padding-top:7px;
}

.block_recent_activitysideblock .h3 {
  padding-top:5px;
}

.block_online_users .listentry div.user,
.block_messages .listentry div.user {
  float:left;
}

.block_online_users .listentry div.message,
.block_messages .listentry div.message {
  float:right;
}

.block_course_list .footer {
  margin-top: 5px;
}

#rssfeeds {
  margin-left: auto;
  margin-right: auto;
}

#block_rss {
  text-align: center;
  border-bottom: 4px;
  
}

.block_search_forums .invisiblefieldset {
  display: none;
}

.block_tag_youtube .youtube-thumb {
  padding: 3px;
  padding-bottom: 3em;
  display: inline;
  float: left;
}
.block_tag_youtube .yt-video-entry li {
  clear: left;
}

.block_tag_flickr .flickr-photos {
 padding:3px;
}