html,
body {
    height: 100%;
}
body {
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    -webkit-box-align: center;
        -ms-flex-align: center;
            align-items: center;
    padding: 40px 0;
    background: #f5f5f5;
    text-align: center;
}
.form-signin {
    width: 100%;
    max-width: 500px;
    padding: 50px 30px;
    margin: auto;
    background: #fff;
    border: 1px solid #ddd;
    border-radius: 5px;
}
.form-content {
    width: 100%;
    max-width: 780px;
    padding: 15px;
    margin: auto;
}