body{margin-top:calc(2rem + 8px)}header{position:fixed;top:0;left:0;width:100%;height:2rem;background-color:#fff;border-bottom:solid black}header>ul{list-style-type:none;margin:0;padding:0}header>ul>li{float:left;display:inline;margin-left:10px}#userInfo{float:right;display:inline;margin-left:10px;background-color:gray}@keyframes rotation{0%{transform:rotate(0)}to{transform:rotate(360deg)}}