.login{
background-size:cover;
position:fixed;
top:0;
left:0;
width:100%;
height:100%;
background: url("../../assets/login.png")no-repeat center center;
}
<div class="login"></div>
.login{
background-size:cover;
position:fixed;
top:0;
left:0;
width:100%;
height:100%;
background: url("../../assets/login.png")no-repeat center center;
}
<div class="login"></div>