body{width:100vw;height:100vh;display:table-cell;vertical-align:middle;background-image: url('img.jpg');background-repeat: no-repeat;background-attachment: fixed;background-size: cover;}#login-frame{width:630px;margin:auto;background:#fff;border:1px solid #dddada;padding:70px}@media (max-width:640px){#login-frame{width:100%;padding:20px}}