html,
body {
    height: 100%;
}

body {
    display: flex;
    align-items: center;
    padding-top: 30px;
    padding-bottom: 30px;
    background-color: #e9e9e9;
}

main {
    width: 100%;
    max-width: 400px;
    margin: auto;
}

.form-signin {
    padding: 30px;
    background-color: #fffafa;
}

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

.form-signin .form-control {
    position: relative;
    box-sizing: border-box;
    height: auto;
    padding: 10px;
    font-size: 16px;
}