<div class="container" id="nav"> <span class="nav-item left" id="user"> <span id="user-id">用户名:41235</span> <span id="user-score">可用积分:0</span> </span> </div> 左右居中

#nav {
    margin: 0 auto;
    width: 1200px;
    height: 50px;
    position: relative;
    }