.nav{width: 93%;height:auto;overflow:hidden;margin: 5.4rem auto 0;}
.nav .nav-list{width: 29%;margin: 0 2.1% 1rem;float:left;position: relative;}
.nav .nav-list img{width:100%;}
.nav-list dl{position: absolute;width:90%;height:90%;left: 0;right: 0;top:0;bottom: 0;margin:auto;}
.nav-list dl dt{width:50%;margin: 10% auto 5%;}
.nav-list dl dt a{display: inline-block;}
.nav-list dl dt a img{width:100%;}
.nav-list dl dd{width: 100%;text-align: center;}
.nav-list dl dd a{color:#fff;font-size: 1rem;}