CSS ÖÐÓ¢Îĵ¼º½

CSS:
<style type="text/css">
a{
  color: #FFFF99;
  text-decoration: none;
}
a:hover{
  color: #FFFFFF;
  text-decoration: underline;
}
  
#nav{
  padding: 10px 10px 0;
  font-size: 12px;
  font-weight: bold;
  margin: 1em 0 0;
  list-style:none;
}
#nav li{
  float: left;
  margin-right: 1px;
}
.bi{
  position: relative;
  z-index: 0;
}
.bi:hover{
  z-index: 99;
}
.bi:hover span{
  visibility: visible;
  top: 0;
  left: 0;
  cursor: pointer;
}
.bi span{
  position: absolute;
  left: -999em;
  visibility: hidden;
}
#nav li a,.bi:hover span{
  line-height: 20px;
  text-decoration: none;
  background: #DDDDDD;
  color: #666666;
  display: block;
  width: 80px;
  text-align: center;
}
#nav li a:hover,.bi:hover span{
  color: #FFFFFF;
  background: #DC4E1B;
}
.bi:hover span{
  padding-top: 2px;
}
#navbar{
  background: #DC4E1B;
  height: 8px;
  overflow: hidden;
  clear: both;
}
</style>
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