html,
body {
    height: 100%;
}

body {
    background-image: url("/images/background.png");
    background-size: cover;
    background-repeat: no-repeat;
    background-position: center;
    -webkit-background-size: cover;
}

.logo-img {
    width: 60%;
    margin: 0px auto 50px;
}

.login-btn {
    padding-bottom: 70%;
}