I know that is a bad summary, but the deal is that trying to style the line/area/bar/pie, etc of a chart is wicked hard and doesn't work like I expected it to. There are just some plain issues here, like you have to do
.series1.default1.chart-series-area-line to set the fill or stroke of the second (first, zero based) series. What's the point in having .series<i>.default<j> if .series1.default0 doesn't work? I expected .series0.default1 to have some affect on the second line segment of the first series, but it doesn't. I also expected .default1.chart-series-area-line to affect the color, but it didn't. This whole scheme either needs revamped or needs to be thoroughly gone over to make sure it works right.