ul{list-style:none;}
img{border:0;}

.banner{width:700px;overflow:hidden;}
.large_box{margin-bottom:10px;width:700px;height:700px;overflow:hidden; border: 1px solid #ddd;
  box-sizing: border-box;}
.large_box li{ text-align: center;}
.large_box li img{height:700px;}
.small_box{width:700px;height:80px;overflow:hidden;}
.small_list{position:relative;float:left;width:650px;height:80px;overflow:hidden;}
.small_list ul{height:80px;overflow:hidden;padding-left: 0;}
.small_list ul li{position:relative;float:left;margin-right:10px;width:80px;border: 1px solid #ddd;box-sizing: border-box;}
.small_list ul li img{display:block;}
.small_list ul li .bun_bg{display:none;position:absolute;top:0;left:0;width:80px;height:80px;border: 1px solid #fd6733;box-sizing: border-box;}
.small_list ul .on {border: 1px solid #fd6733;}
.btn{display:block;width:20px;height:80px;background-color:#bbb;background-repeat:no-repeat;background-position:center center;cursor:pointer;}
.btn:hover{background-color:#000;}
.left_btn{float:left;margin-right:10px;background-image:url(../images/left_btn.png);}
.right_btn{float:right;background-image:url(../images/right_btn.png);}

.product_detail{
border-top: 1px solid #ddd;
padding-top: 30px;
}
.product_detail .title{
  font-size: 30px;
}
.product_detail .btn_box{
      background: #000;
    padding: 7px 20px;
    display: inline-block;
    text-decoration: none;
    
}
.product_detail .btn_box .b{
color: #fff;
    font-size: 16px;
}
.product_detail_title{
  font-size: 30px;
  margin-top: 50px;
  padding-bottom: 15px;
  border-bottom: 1px solid #ddd;
}