#head {
    margin: 0 auto -290px -960px;
    z-index: 999;
    position: fixed;
    top: 0;
    left: 50%;
    width: 1920px;
    height: 75px;
    background-color: #000;
    color: #fff;background:url(../images/head.png) no-repeat left top;
  }
  
  #head .menu {position: absolute;margin-left: 1217px;margin-top: 15px;}
  #head .menu ul {
    list-style-type: none;
    list-style: none;
    display: block;
    margin: 0;
    padding: 0;
  }
  #head .menu ul li {
    text-align: center;
    margin: 8px;
    float: left;
    width: 140px;
    height:57px;
    display: block;font-size: 0;
  }
  #head .menu ul li a{width: 140px;height:57px;display: block;}
  #head .menu ul li.ht1 {}
  #head .menu ul li.ht2 {margin-left: 101px;}
  #head .menu ul li.ht3 {margin-left: 103px;}
  
  
  #head .menu ul li.ht1:hover {background:url(../images/active1.png) no-repeat left top;}
  #head .menu ul li.ht2:hover {background:url(../images/active2.png) no-repeat left top;}
  #head .menu ul li.ht3:hover {background:url(../images/active3.png) no-repeat left top;}