div.center {
    display: flex;
    justify-content: center;
}

div.body {
    width: 40%;
    min-height: 200px;
    background-color: white;
    border: 3px solid;
    border-color: #000033;
    border-radius: 8px;
    padding: 10px;
}

div.titlebar {
    display: inline-flex;
}

body {
    background-color: gray;
}