body {
    margin: 0;
    padding: 0;
    background-color: black; 
}

.container {
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center; 
    width: 100%;
    max-width: 450px; 
    margin: 0 auto; 
}


.container img.background {
    width: 100%; 
    height: auto; 
    display: block;
}


.container img.btn_overlay {
    position: absolute;
    top: 0;
    right: 0;
    margin-right: 10px;
    margin-top: 20px;
}

.container a.btn_download {
    position: absolute;
    top: 50%; 
    left: 50%; 
    margin-left: -180px; 
    margin-top: -150px;  
}

.container a.btn_download img {
    width: 100%; 
    height: auto; 
}