the second chart on https://observablehq.com/@dmaynard/covid-19-us-states-explorer collapses the x axis into one pixel in portrait mode in both Chrome and Safari on my iPhone 7. If I rotate the phone to landscape mode it renders properly.
Any suggestions? Is this a perhaps a vega-lite issue? The same problem does not occur on the first chart on the page even though the chart and the data are very similar to the second chart.