Changelog, support for dark theme in document root

src/css/common.scss

@@ -38,6 +38,10 @@ html {
     right: 0;
 
     background: #dee1ea;
+
+    @include DarkThemeOverride {
+        background: #5c606c;
+    }
 }
 
 body {

src/css/mixins.scss

@@ -350,7 +350,7 @@ button,
 }
 
 @mixin DarkThemeOverride {
-    @at-root body[data-theme="dark"] &,
+    @at-root html[data-theme="dark"] &,
         &[data-theme="dark"] {
         @content;
     }

src/css/textual_game_state.scss

@@ -61,4 +61,21 @@
             }
         }
     }
+
+    @include DarkThemeOverride {
+        .headerBar {
+            h1 {
+                color: #cfceca;
+            }
+
+            .backButton {
+                filter: invert(1);
+            }
+        }
+
+        > .container > .content {
+            background: #4b4c50;
+            color: #eee;
+        }
+    }
 }