I have primarily tested on Chrome, a little on Safari and Firefox, and not at all with Internet Explorer (at least IE9 would be required).
The spending and receipts data files are from the OMB's Public Budget Database, available at http://www.whitehouse.gov/omb/budget/supplemental. Specifically, the "Outlays" csv file and the "Receipts" csv file. These contain both historical and projected data, going back to 1962 and up to 2019. I have spot-checked the rolled-up values against the corresponding values in the Historical Tables file from the gpo (which checked out), but this is still a work-in-progress.
Perhaps obvious, but I have decided that every single possible screen size requires a potentially completely different interface design, with unique decision encumbrances for all of them. Each may present a nice little puzzle, but there are a wearying number of them. And it is difficult to predict ahead of time what the necessary adjust will be be: you have to see it.
So far, I have attempted to deal with a handful of cases, a few of which are listed below. I have tested only on Chrome on a Mac, an iPad, and an iPhone. It will be interesting to see how well the other browsers handle it.
In this case, all of the features are available, and you can explore the detail tables.
In this case, there are no detailed breakdowns available, but there's sufficient space for the horizontal scroll region at the bottom, where you can select different years.
In this case, there are no detailed breakdowns available, nor does the horizontal scroll area have enough room (per my current parameters), but you can change years and see the totals and how the spending breaks down in terms of mandatory, interest, and discretionary.
I have yet to deal with iPhone landscape.
In some cases, the red bar for the deficit is too small for a label. In these cases, the label dynamically slides out when you select one of these years, and tries to be as non-vertical as possible (there's a little leeway still to optimize, I think). An example is shown below. It's debatable if angled text is any easier to read than vertical text, but maybe it's the thought that counts.
but not going vertical, on a small screen
I have a healthy number of TODO's yet to get to - improve the performance of the rendering of the detail tables, better synchronize the animations - and there might be more important ones that come up based on initial feedback.