body,html{
  width: 100%;
  height: 100%;
  background-image: url('../img/yxbhzxt_back.png');
  background-size: 100% 100%;
}
/*.main{
  width: 1000px;
  height: 486px;
  position: absolute;
  left:50%;
  top:50%;
  margin-left: -500px;
  margin-top: -243px;
  font-size: 14px;
  text-align: center;
}*/
.main ul{list-style: none;width:1000px;margin:auto;}
.main ul .left{
  float: left;
}
.main ul .right{
  float: right;
}