[Affected Versions]:

• Firefox Beta 80.0b1 (build ID: 20200728204253)
• Firefox Nightly 81.0a1 (build ID: 20200728213249)
• Firefox Release 79.0 (build ID: 20200720193547)
• Chrome 84.0.4147.105
• Firefox for Android 68.11.0
• Firefox for iOS 27.0

[Affected Platforms]:

• Windows 10
• Linux Mint 19.2
• Android 10
• iOS 12.4.6

[Prerequisites]:

• You are using a mobile device or a desktop browser window small enough to display the mobile version of the website.
• You are on the Treatment branch.

[Steps to reproduce]:

1. Click the “Share Monitor” button from the footer.
2. Observe the text field and the “Copy” button.

[Expected results]:

• The button is the same size as the text field.

[Actual results]:

• The button and the text field are of different sizes.

[Notes]:

• This is also reproducible for the Specific Message modal.
• Attached is a screenshot of the issue.