.login-bg{width:100vw;height:100vh;background:url(https://demo-1301844204.cos.ap-shanghai.myqcloud.com/bg-login.png) no-repeat 50%;background-size:cover;position:relative}.login-panel{width:90vw;margin-left:5vw;position:absolute;top:28vh}.login-panel button{margin-bottom:10px}