html,
body {
    height: 100%;
}

body {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding-top: 40px;
    padding-bottom: 40px;
}

.form-signin {
    width: 100%;
    max-width: 330px;
    padding: 15px;
    margin: auto;
}

.form-signin .checkbox {
    font-weight: 400;
}