When this input is interacted with, the height of the chart changes, and therefore the input moves vertically. Therefore, maybe it would be nice to put the input above the chart, so that it doesn't move around when interacted with?

yeah - my intent was to introduce the faceting, and then bring in the inputs that control the facets... but I agree with you that the goal of not having the inputs move when you use them is more important. Thanks for the comment! I implemented the change.