*{box-sizing:border-box}.header{background-color:#000;overflow:hidden;padding:20px 40px 10px;position:fixed;top:0;width:100%;z-index:1}.header-right a{border-radius:4px;color:#000;float:left;font-size:18px;font-weight:700;padding:12px;text-align:center;text-decoration:none}.header a.logo img{width:140px}.header a.active{background-color:#1e90ff;color:#fff}.header-right{float:right}@media screen and (max-width:500px){.header a.logo img{width:120px}}