Empty tab bar is shown on opening

[kjvdven]

Captchas

• [X] I have read the instructions.
• [X] I have searched existing issues and avoided creating duplicates.
• [X] I am not filing an enhancement request.

What happened?

When navigating with tab bar and top bar hidden (compact mode), I get an empty sidebar on use. This only goes away when I hover over it. When hovering I get a normal tab bar, with tabs.

f.e. when opening the settings.

I don't know if this related, but sometimes, when I have compact mode enabled, the top bar is visible covering the top of the page.

Reproducible?

• [ ] I have checked that this issue cannot be reproduced on Mozilla Firefox.

Version

1.0.1-a.17 (Firefox 132.0) (aarch64)

What platform are you seeing the problem on?

macOS - aarch64

Relevant log output

No response

[dosubot[bot]]

Hey there, @kjvdven! I'm here to help you with any bugs, questions, or contributions you have. Let's work together to solve this issue.

The issue you're experiencing with the empty tab bar in compact mode on macOS is likely related to the CSS settings for the #navigator-toolbox. In version 1.0.1-a.17 on Firefox 132.0, the CSS sets the opacity of the #navigator-toolbox to 0 by default, making it invisible until you hover over it, which changes the opacity to 1 and makes it visible. This behavior is controlled by the following CSS snippet:

#navigator-toolbox {
    ...
    opacity: 0;
    ...
}

#navigator-toolbox:hover,
#navigator-toolbox[zen-has-hover],
#navigator-toolbox:focus-within,
#navigator-toolbox[zen-user-show],
#navigator-toolbox[flash-popup],
#navigator-toolbox[has-popup-menu],
#navigator-toolbox[movingtab],
#mainPopupSet:has(> #appMenu-popup:hover) ~ toolbox,
#navigator-toolbox:has(.tabbrowser-tab:active),
#navigator-toolbox:has(*[open='true']:not(tab):not(#zen-sidepanel-button)) {
    opacity: 1;
    ...
}

This CSS rule is responsible for the tab bar's visibility behavior in compact mode ^[1].

To continue talking to Dosu, mention @dosu.

[RayZ3R0]

It happens in some other cases too, weird bug

https://github.com/user-attachments/assets/4550758c-5df1-44eb-81e9-10baeb6a3810