hypothesis
When viewport shrinks, transition from side-by-side to overlap more gracefully
This is a suggested improvement to the PDF side-by-side experience.
Current behavior As you shrink the browser window, when the viewport becomes too narrow to support both the sidebar and the PDF, the PDF starts to shrink-- until a certain point, after which the sidebar snaps to completely overlap the PDF, and the underlying PDF expands again to fill that additional space. Keep narrowing still and then eventually the PDF begins to shrink again. So--the PDF shrinks in two steps, in kind of “sawtooth” fashion.
I'm not able to embed the GIF @dwhly created to show what this looks like, as it exceeds the file limit of 10MB. Here's a link to the GIF in Slack.
Desired Behavior As the viewport narrows, sidebar goes from being side-by-side to partially overlapping and then completely overlapping without ever shrinking the PDF, until the PDF itself must shrink because the browser is simply too narrow.
