html,body,div,ul,li,a { margin:0px; padding:0px; } body { font-size:14px; font-family:"微软雅黑"; background:#333; } ul { list-style:none; } a { text-decoration:none; } .header { height:50px; background:#128a28; } .header .nav { width:1000px; height:50px; line-height:50px; margin:0 auto; position:relative; z-index:111; } .header .nav li { float:left; width:14.28%; height:50px; line-height:50px; text-align:center; } .header .nav li a { color:#fff; } .header .nav li .second-nav { width:150px; display:none; position:relative; } .header .nav li .second-nav li { position:relative; width:100%; height:40px; line-height:40px; background:#128A28; border-top:1px solid #097d1f; } .header .nav li .second-nav li .third-nav { /*position:absolute; */ width:150px; height:200px; display:none; margin-left:100%; margin-top:-40px; }