*{ margin:0; padding:0; list-style:none}
.trans {
    /*transition*/
    -webkit-transition: 0.3s ease;
    -moz-transition: 0.3s ease;
    -ms-transition: 0.3s ease;
    -o-transition: 0.3s ease;
    transition: 0.3s ease;
}
.left_btn,.right_btn{ position:absolute; width:30px; height:40px; top:40%; cursor:pointer; background:rgba(0,0,0,.5); z-index:88; text-align:center; line-height:40px; color:#CCC; font-size:30px;}
.left_btn{ left:-30px;}
.right_btn{ right:-30px;}
.bd:hover .left_btn{ left:0}
.bd:hover .right_btn{ right:0}
.bd{ width:1000px; height:400px; outline:#999 4px solid; margin:50px auto;overflow:hidden; position:relative;}
.bd .box{ width:6000px; position:absolute; top:0 ; left:0;}
.bd ul{ overflow:hidden; width:3000px; float:left}
.bd ul li{ height:400px; width:1000px; float:left; text-align:center; font-size:50px; line-height:400px;}