ul.horizontal li {
  display: inline-block;
}

#header #primary.menu ul li {
  color: #555;
  background-color: #fff;
  padding: 10px;
  margin: 0;
}
#header #primary.menu ul li a {
  color: #555;
  text-decoration: none;
}
#header #primary.menu ul li a:hover {
  color: black;
}
#header #primary.menu ul.horizontal {
  border-bottom: solid 1px #ddd;
}
#header #primary.menu ul.horizontal li {
  border-top: solid 3px #fff;
}
#header #primary.menu ul.horizontal li:hover {
  background-color: #ffe;
  border-top: solid 3px #999;
}
#header #primary.menu ul.horizontal li.active {
  font-weight: bold;
  border-top: solid 3px #ddd;
  background-color: #ddd;
}
#header #primary.menu ul.horizontal li.active:hover {
  border-top: solid 3px blue;
}

#content {
  margin-left: 20px;
}

.sidebar {
  padding: 5px;
  margin: 3px;
  border: solid 1px #ccc;
}
.sidebar#sidebar_first {
  width: 250px;
  float: left;
}
.sidebar#sidebar_second {
  width: 250px;
  float: right;
}