html,body{width:100%;height:100%;margin:0;padding:0}.inner{width:1140px;margin:auto;position:relative}@media(min-width:1200px){.inner{width:80%}}header{width:100%;height:80px;line-height:80px;font-size:32px;background-color:#171d25;color:#fff}footer{border-top:1px solid #c3c3c3;margin-top:40px;padding-top:4px;padding-bottom:4px}.flex{display:flex}.fl{float:left}.fr{float:right}#content{min-height:500px}