"

From 2013.igem.org

.pop {

 position: absolute;
 display: inline; }
 .pop .pop_menu {
   display: none;
   -moz-border-radius: 3px;
   -webkit-border-radius: 3px; }
 .pop .pop_toggle {
   background-image: url();
   background-repeat: no-repeat;
   background-position: center center;
   width: 20px;
   height: 20px;
   overflow: hidden;
   cursor: pointer; }

.active .pop_menu {

 display: block;
 background-color: #F594A2;
 color: #fff;
 position: absolute;
 padding: .6em;
 width: 12em; }
 .active .pop_menu a {
   color: #fff; }

.active .pop_toggle {

 z-index: 2000;
 position: absolute;
 top: 0;
 left: 0;
 background-image: url(); }