1958487 - Tab group lines can be hard to see for themes that use contrasting colors in toolbar due to lack of margin

Status: RESOLVED FIXED

(Firefox :: Tabbed Browser, defect, P2)

Description

[Kestrel]

Attachment: Comparison of tab group line visibility with contrasting theme colors between stock (top) and userChrome fix (bottom)

STR:

1. Enable horizontal tabs.
2. Install a theme with a dark tabbar/titlebar and light toolbar (eg Arc Darker Theme (3,000 users), Photon Colors (2,551 users), Classic System Theme (710 users), Black and White (352 users)).
3. Create multiple tab groups with different colors.

Expected:
Tab group lines are separated from toolbar edge, making them more defined regardless of theme colors.

Actual:
Tab group lines have no margin or padding from the toolbar edge, making them hard to see with contrasting theme colors. The brightness of the toolbar bleeds over and makes the group lines less distinct, especially with mild vision impairment which can be simulated by squinting/unfocusing eyes.

Container lines are unaffected as they have padding/margins from both the tab and the window edge.

userChrome.css workaround:

.tab-group-line {
  margin-bottom: -3px !important;
}

.tab-group-label-container {
  margin-bottom: 1px !important;
}

Comment 1

[Dão Gottwald [:dao]]

Attachment: Bug 1958487 - Move tab group line away from the toolbar border. r?dwalker

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/7e69d9a7e6f7
Move tab group line away from the toolbar border. r=dwalker,tabbrowser-reviewers

Comment 3

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/7e69d9a7e6f7

Comment 4

[BugBot [:suhaib / :marco/ :calixte]]

The patch landed in nightly and beta is affected.
:dao, is this bug important enough to require an uplift?

• If yes, please nominate the patch for beta approval.
• If no, please set status-firefox138 to wontfix.

For more information, please visit BugBot documentation.