Tweak color palette and dark mode

Author: rocka

mkdocs.yml

@@ -3,8 +3,20 @@ site_description: Documentation for fcitx5-android
 theme:
   name: material
   palette:
-    primary: teal
-    accent: teal
+    - media: "(prefers-color-scheme: light)"
+      scheme: default 
+      primary: teal
+      accent: amber
+      toggle:
+        icon: material/brightness-7
+        name: Switch to light mode
+    - media: "(prefers-color-scheme: dark)"
+      scheme: slate
+      primary: teal
+      accent: amber
+      toggle:
+        icon: material/brightness-4
+        name: Switch to dark mode
   favicon: assets/ic_launcher_legacy_source.png
   logo: assets/ic_launcher_legacy_source.png
   features: