SVG elements seem to render on top of the month picker

[piperswe]

Here's a screenshot. The chart is from react-google-charts, which uses the Google Visualization API which renders charts as SVG elements. The download button is from material-ui-icons, which uses SVG elements as well. No other element seems to render on top of the month picker.

I've tried to tweak the z-index of everything imaginable to no avail. What might be causing this problem?

[nickeljew]

Where is the download button?
Which element's z-index did you set?
Can you show me the codes about those SVG elements?

[piperswe]

The download button is the little download symbol below the bottom left of the chart.
I've set the z-index of every element above the cell on the month picker.
The website is at http://courtstatpack.com, and you can see the SVGs at https://gist.github.com/zebMcCorkle/963ce6031b8b8add9ca457b79d5ce3c5 (though for some reason Gist doesn't like to render them)