*{ margin:0; padding:0; list-style:none;}
.bg{ margin:50px auto; width:363px;}
.bg .hd{ overflow:hidden; width:363px; background:#ececec; border-top:1px solid #ccc;border-left:#CCC 1px solid;}
.bg .hd li{ float:left; height:30px; width:120px; line-height:30px; text-align:center; border-right:#CCC 1px solid;border-bottom:#CCC 1px solid;}
.bg .bd li{ width:362px; height:360px; text-align:center; line-height:360px; border:#CCC 1px solid; border-top:0; display:none;}
.bg .hd .on{ background:#fff;border-bottom-color:#fff;}
.bg .bd .on{ display:block;}