html,
body {
    height: 100%;
}
body {
    display: -ms-flexbox;
    display: -webkit-box;
    display: flex;
    -ms-flex-align: center;
    -ms-flex-pack: center;
    -webkit-box-align: center;
    align-items: center;
    -webkit-box-pack: center;
    justify-content: center;
    padding-top: 40px;
    padding-bottom: 40px;
}
.form-signin {
    width: 100%;
    max-width: 330px;
    padding: 15px;
    margin: 0 auto;
}
.logo-container {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 10px;
}
.logo {
    width: 100%;
    max-width: 150px;
    height: auto;
}
@media (min-width: 600px) {
    .logo {
        max-width: 200px;
    }
}
@media (min-width: 900px) {
    .logo {
        max-width: 250px;
    }
}