Dark mode compatible logo (#2532)

README.md

@@ -10,7 +10,7 @@
 [![Anaconda-Server Badge](https://img.shields.io/conda/vn/conda-forge/ESMValCore?color=blue&label=conda-forge&logo=conda-forge&logoColor=white)](https://anaconda.org/conda-forge/esmvalcore)
 [![Github Actions Test](https://github.com/ESMValGroup/ESMValCore/actions/workflows/run-tests.yml/badge.svg)](https://github.com/ESMValGroup/ESMValCore/actions/workflows/run-tests.yml)
 
-![esmvaltoollogo](https://raw.githubusercontent.com/ESMValGroup/ESMValCore/main/doc/figures/ESMValTool-logo-2.png)
+![esmvaltoollogo](https://raw.githubusercontent.com/ESMValGroup/ESMValCore/main/doc/figures/ESMValTool-logo-2-glow.png)
 
 ESMValCore: core functionalities for the ESMValTool, a community diagnostic
 and performance metrics tool for routine evaluation of Earth System Models

doc/conf.py

@@ -170,8 +170,13 @@
 # Short synopsis of said issue: as of now, left/right keys take one
 # to the previous/next page instead of scrolling horizontally; this
 # should be fixed upstream, then we can set again navigation with keys True
-html_theme_options = {"navigation_with_keys": False}
-
+html_theme_options = {
+    "navigation_with_keys": False,
+    "logo": {
+        "image_light": "figures/ESMValTool-logo-2.png",
+        "image_dark": "figures/ESMValTool-logo-2-dark.png",
+    },
+}
 # Add any paths that contain custom themes here, relative to this directory.
 # html_theme_path = []
 
@@ -194,7 +199,7 @@
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
-html_static_path: list = []
+html_static_path: list = ["figures/ESMValTool-logo-2-dark.png"]
 
 # Add any extra paths that contain custom files (such as robots.txt or
 # .htaccess) here, relative to this directory. These files are copied