Affected versions

• 86.0, 87.0b7, 88.0a1(2020-03-08)

Affected platforms

• Windows 10, macOS 10.15;

Steps to reproduce

1. Launch Firefox, right click on the toolbar and pick the Customize option;
2. Grab the browser and size it so the bottom section buttons just barely fit and are all displayed on the same line;
3. Customize the browser in any way (moving a button on any valid location);
4. Click on the Restore Defaults button;

Expected result / Enhancement suggestion

• encapsulate the 3 buttons in a div and make it float right so that the [Done] button would not end up on the other browser side

Actual result

• buttons float to left 1 by 1;

Regression range

• not a regression;

Additional notes

• small UX suggestion, so that the button(s) would keep a more expected position on browser resize or certain screen resolutions;
• attached recording to best illustrate the issue/suggestion.