terminal tour pane is partially not visible

[DrXyzzy]

Seen in: Chrome, Firefox, and Safari.

1. sign into cocalc and open a project
2. open a .term file
3. click the "Tour" button in the top toolbar just left of the "ChatGPT" button
4. observe that the pop-up panel is too far to the left, with much of it out of the window

Screenshot from Chrome: