Web Stories preview in FireFox browser has virtual devices spilling off screen

[adamdunnage]

Description

When using the preview function in Web Stories from a FireFox browser the virtual devices displayed are spilling off the screen. If you minimise the browser window to a certain level they will disappear entirely and aren't responsive.

This only seems to happen when using a FireFox browser and other browsers do not do this.

Screenshot with browser window maximised:

Screenshot with browser window smaller:

Reproduction Steps

1. Open up a Web Story in the editor mode.
2. Select the Preview option.
3. Minimise/maximise the browser window size.

Relevant Logs

No response

Browser(s) Affected

Firefox

OS(s) Affected

No response

Device(s) Affected

No response

AMP Version Affected

No response