Microsoft Edge: Transparent header in 5.x

Description

Microsoft Edge displays a transparent header in mkdocs-material 5.x. In the previous 4.x releases, Microsoft Edge used to display the background color correctly as defined in theme['palette']['primary'].

I’ve noticed that if you inspect the corresponding md-header DOM element, it will show you that the CSS attribures color/background-color are set correctly to var(--md-primary-fg-color)/var(--md-primary-bg-color). So my guess is that there is something wrong with the fade-in animation; browser-specific instructions my be needed.

Expected behavior

Edge renders the header background color as defined in theme['palette']['primary']

Actual behavior

Edge renders a transparent header background

Steps to reproduce the bug

1. Serve a mkdocs documentation with the mkdocs-material enabled
2. Open documentation in Edge

Package versions

• Python: 3.7.3
• MkDocs: 1.1.2
• Material: 5.2.1

Project configuration

theme:
  name: material
  language: en
  features:
    - instant
  palette:
    scheme: default
    primary: grey
    accent: blue
  font:
    text: Roboto
    code: Roboto Mono
  logo: img/logo.png

System information

• OS: Windows 10
• Browser: Edge 44

[squidfunk]

Fixed in 24b185a7.

[squidfunk]

Released as part of 5.2.2