html, body {
    background-color: #9E5932;
}

.wrapper {
    position: absolute;
    top: 0;
    left: 0;

    width: 100%;
    height: 100%;
    text-align: center;
}

.header {
    position: absolute;
    top: calc(50% - 150px);
    left: calc(50% - 200px);

    height: 300px;
    width: 400px;
    color: #FFF5E1;
}