/************************
 * Color Background *****
************************/
html.sm-user-ui  {
    background-image: url(https://photos.smugmug.com/photos/i-fGpcNs8/1/171040b1/X3/i-fGpcNs8-X3.jpg);
    background-repeat: no-repeat;
    background-position: center top;
    background-attachment: fixed;
    background-size: 100%;
}

@media screen and (max-width: 768px) {
    html.sm-user-ui  {
        background-size: auto;
    }
}