html, body {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    display: table;
    font-size: 14px;
}
#outer {
    display: table-cell;
    text-align: center;
    vertical-align: middle;
    background-color: #f1f1f1;
}
#inner {
    color: #444;
    font-family: "Open Sans",sans-serif;
    margin: auto;
    max-width: 500px;
    padding: 20px;
    background-color: #fff;
    box-shadow: 0 1px 3px rgba(0,0,0,.13);
}
#pay_info {
    font-size:medium;
}