Description

When editing a legacy menu widget in the Customizer in Firefox, the text for dropdown menus is misaligned. It works correctly on the Widgets admin screen.

Step-by-step reproduction instructions

1. Add a menu to the site.
2. Open the Widgets panel in the Customizer.
3. Insert a legacy navigation widget.
4. Observe the dropdown text is pulled out of the field.

Expected behaviour

The text is properly aligned within the field.

Actual behaviour

It is not.

Screenshots or screen recording (optional)

WordPress information

• WordPress version: 5.8 RC3
• Gutenberg version: Not installed
• Are all plugins except Gutenberg deactivated? Yes
• Are you using a default theme (e.g. Twenty Twenty-One)? Yes

Device information

• Device: Macbook
• Operating system: MacOS 10.15.x
• Browser: Firefox nightly (91.0a1 (2021-07-09) (64-bit)), but also found in 89.