form input[type=button] {
  -webkit-border-radius: 5px;
  -moz-border-radius: 5px;
  border-radius: 5px;
}
#logo:hover {
  opacity: 0.5;
  filter: progid:DXImageTransform.Microsoft.Alpha(Opacity=50);
}
/* parente references */
table tr {
  background-color: #eee;
}
table tr.even,
table tr:nth-child(even) {
  background-color: #fff;
}
table td {
  padding: 4px 10px;
}
table#users tr {
  background-color: #494848;
}
table#users tr.even,
table#users tr:nth-child(even) {
  background-color: #303030;
}
table#users td {
  color: #fff;
}
/* block mixing */
.bar {
  width: 10px;
}
/* mixing in mixing */
ul li {
  display: inline;
}
ul li:after {
  content: ', ';
}
ul li:last-child:after {
  content: '';
}