scyfin/CSS/chapters-on-player.css

/* Display chapters on time bar */
.sliderMarker {
    position: absolute !important;
    width: 2px !important;
    height: 9.5px !important;
    transform: translate3d(0, 50%, 0) !important;
    display: block !important;
}

.sliderMarker.unwatched {
    background-color: rgba(255, 255, 255, 0.3) !important;
}

.sliderMarker.watched {
    background-color: #007da7 !important;
    z-index: 1 !important;
}

/* Remove first and last chapters */
.sliderMarker:first-of-type.unwatched {
    background-color: transparent !important; 
}

.sliderMarker:last-of-type.unwatched {
    background-color: transparent !important; 
}

.sliderMarker:first-of-type.watched {
    background-color: transparent !important; 
}

.sliderMarker:last-of-type.watched {
    background-color: transparent !important; 
}