Switch default dark mode filter

lang/en-EN/game.xml

@@ -14,6 +14,7 @@
             • Dark theme now has different variants to choose from, representing different color filter methods, so you can choose which works best for your computer/monitor/eyes/taste. Thank you to zenonline for making the request!<br>
             • Enabling the predictor no longer causes the action list to overflow in the experimental responsive UI. (This is part of why it's called "experimental".)<br>
             • The game will no longer attempt to keep an empty action list active, even if the checkbox is checked.<br>
+            • Switched the default dark mode variant to one that's better for legibility, especially with the predictor. Previous default was "Matrix 2", now is "Matrix 4".<br>
             ]]></version>
             <version verNum="3.P16.6"><![CDATA[
             <b> Dec 2nd, 2023</b>

stylesheet.css

@@ -884,7 +884,7 @@ input[type="number"] {
 
 .t-dark {
     filter: invert(1) hue-rotate(180deg);
-    filter: url(#inversion2);
+    filter: url(#inversion4);
     background: #111;
     color: #222;
 }