Bounce back on mobile isn't clear

It seems if the width of the window is too small, then the bounce back effect doesn't scroll far enough to show the edge of the content. It still does the bounce back, but it isn't clear that it happened. I can reproduce this with a small enough desktop browser window as well.

Reproduce the bounce-back behavior in a narrow mobile or desktop browser window and trace the relevant scrolling entry point in the JavaScript source. Done means the bounce visibly reveals the content edge while preserving the existing bounce-back effect.

Written by the indexing model from the issue text.