Tabs are using "dark mode" styles on launch of the app

[pedrodonkey]

OS macOS Big Sur - 11.2.3

Gmail Desktop Version Version 3.0.0-alpha.14 (3.0.0-alpha.14)

Describe the bug Tabs are using "dark mode" styles on launch of the app.

Steps to reproduce the behavior

1. Launch the app
2. Settings > Dark Mode > Follow System Appearance is checked by default
3. Selecting Follow System Appearance again seems to fix the issue until next re-launch

Expected behavior Normal tab styles seeing as Follow System Appearance is checked by default and not Dark mode tab styles.

Media On Launch with Follow System Appearance checked:

Re-selecting Follow System Appearance:

Video

https://user-images.githubusercontent.com/1678763/112338039-25790200-8cc7-11eb-8152-4ffc44ef684b.mov