2051200 - [Nova] The X button of the “SIDEBAR_FEATURE_TOUR” message doesn’t display the Nova circle hover effect on dark theme

Status: RESOLVED DUPLICATE of bug 2051205

(Firefox :: Messaging System, defect)

Description

[Simona Rosu [:srosu], Ecosystem QA, PTO until September 8 - NI to: [e-mail]]

Attachment: ScreenshotOfTheIssue.png

[Notes]:

• This issue appears to be reproducible only on this message.

[Affected versions]:

• Firefox Nightly 154.0a1 (Build ID: 20260628214348)

[Affected Platforms]:

• Windows 10 x64
• macOS 15.7.3
• Ubuntu 24.04.1

[Prerequisites]:

• Have the latest Firefox Nightly 154.0a1 build installed/extracted and opened.
• Have the “browser.nova.enabled” and “browser.newtabpage.activity-stream.asrouter.devtoolsEnabled” prefs set to true;
• Have the Nimbus Devtools extension installed.
• Have the Dark theme enabled.

[Steps to reproduce]:

1. Force enroll in the “Expand vertical tabs callout (existing profiles)” rollout using the Nimbus Devtools extension.
2. Restart the browser, navigate to about:asrouter, and search for “SIDEBAR_FEATURE_TOUR” callout message.
3. Click the “Show” button and hover the “x” button in the message.
4. Observe the button area.

[Expected result]:

• The “X” button displays a Nova styling hover effect.

[Actual result]:

• No Nova hover effect is displayed on the “X” button.

[Additional Notes]:

• Attached is a screenshot of the issue.