.reveal.coursemod__presentation {
    display: inline-block;
    position: relative;
    width: 100%;
}

.coursemod__presentation--coursemod-active {
    width: 66.66%;
}

/*
    make sure the controls and everything else stays inside the presentation view
*/
.reveal.coursemod__presentation .controls,
.reveal.coursemod__presentation .audio-controls,
.reveal.coursemod__presentation .recorder,
.reveal.coursemod__presentation .slide-number {
    position: absolute
}

.coursemod__course-view {
    background-color: white;
    border-left: 2px solid black;
    box-sizing: border-box;
    display: none;
    height: 100%;
    overflow-x: scroll;
    padding: 0 10px;
    position: fixed;
    right: 0;
    top: 0;
    width: 33%;
}

.coursemod__presentation.coursemod--active {
    width: 66.66%;
}

.coursemod__course-view.coursemod--active {
    display: inline-block;
}
.reveal.coursemod__presentation {
    display: inline-block;
    position: relative;
    width: 100%;
}

.coursemod__presentation--coursemod-active {
    width: 66.66%;
}

/*
    make sure the controls and everything else stays inside the presentation view
*/
.reveal.coursemod__presentation .controls,
.reveal.coursemod__presentation .audio-controls,
.reveal.coursemod__presentation .recorder,
.reveal.coursemod__presentation .slide-number {
    position: absolute !important;
}

.coursemod__course-view {
    background-color: white;
    border-left: 2px solid black;
    box-sizing: border-box;
    display: none;
    height: 100%;
    overflow-x: scroll;
    padding: 0 10px;
    position: fixed;
    right: 0;
    top: 0;
    width: 33%;
}

.coursemod__presentation.coursemod--active {
    width: 66.66%;
}

.coursemod__course-view.coursemod--active {
    display: inline-block;
}
Add important to absolute rule
Add important to absolute rule
