The design is broken on the navigation layout page in dark mode

Problem/Motivation

The design on admin/config/user-interface/navigation-block is broken:

Steps to reproduce

• switch to dark mode
• go to admin/config/user-interface/navigation-block
• enable the edit mode

Proposed resolution

Fix the background color of the navigation blocks, adjusting it to the correct background color for dark mode and adjust the color of their menu item labels accordingly, that also have aside the break of styling a too low color contrast currently (SC1.4.3). The block with the status message needs to adjust the background color as well.

For the add block button i'll open a separate issue and link in here afterwards. it has a too low color contrast (WCAG2.2 SC1.4.11) but the problem applies to the light and dark. and the problem of the menu item for the current page that applies to the navigation layout page as well is already covered in 🐛 Improve the color contrast for the menu item of the current page Active .

Remaining tasks

User interface changes

API changes

Data model changes