#CourseHeader {
    background-image: url("headers/app-1x.jpg");

    background-color: #eaf8eb;
    background-repeat: no-repeat;
    background-size: contain;
    background-position: center;
    /*background-blend-mode: overlay;*/
    background-position-x: right;
    background-position-y: bottom;

    padding-top:3em;
    padding-bottom:6em;

    overflow:visible;
}
#AppScreen {
    width:25vw;
    max-width:315px;
    height:auto;
    z-index:999;
}
/* Small devices (landscape phones, 576px and up) */
@media (min-width: 576px) {
    /*html {font-size: 0.87rem;}*/
    #CourseHeader {
        background-image: url("headers/app-2x.jpg");
    }
}

/*// Medium devices (tablets, 768px and up)*/
@media (min-width: 768px) {
    /*html {font-size: 0.93rem;}*/
    #CourseHeader {
        background-image: url("headers/app-3x.jpg");
    }

}

/*// Large devices (desktops, 992px and up)*/
@media (min-width: 992px) {
    /*html {font-size: 1rem;}*/
    #CourseHeader {
        background-image: url("headers/app-4x.jpg");
    }

}

/*// Extra large devices (large desktops, 1200px and up)*/
@media (min-width: 1200px) {
    #CourseHeader {
        background-image: url("headers/app-5x.jpg");
    }
}