*{margin:0; padding: 0}
html,body{width: 100%; height: 100%; position: relative; background-color: #000;}
.banner_box{width: 100%; height: 68%; overflow: hidden;position:absolute;}
.banner_show{width: 100%; height: 100%;display: -webkit-box;display: -moz-box;display: -ms-flexbox; display: -webkit-flex;display: flex;position: relative;}
.banner_show div{width: 100%; height: 100%;position: relative;background-position: center center;background-size: cover;  -webkit-flex-shrink: 0;-ms-flex: 0 0 auto;flex-shrink: 0;}
.dot_box{width: 50%; height: 20px;position: absolute; left: 25%;bottom: 10px;font-size: 0;left:50%;}
span{display: block;}
.dot{width: 18px; height: 18px; border-radius: 50%; background: #fff;display: inline-block;position: relative; }
.dot_margin{margin-left:18px;}
.dot_selected{background: #000;}
.banner_show{width: 100%; height: 100%;position: relative;background-position: center center;background-size: cover;}
.banner_img{width: 100%; height: 100%;position: relative;background-position: center center;background-size: cover;}