Fix grass mirroring: use dedicated flipped keyframe animation instead of inline transform that was overridden by grassSway

game.js

@@ -1445,7 +1445,7 @@ class Game {
       span.style.top               = y + 'px';
       span.style.animationDelay    = (Math.random() * 4).toFixed(2) + 's';
       span.style.animationDuration = (2 + Math.random() * 2).toFixed(1) + 's';
-      if (Math.random() > 0.5) span.style.transform = 'scaleX(-1)';
+      if (Math.random() > 0.5) span.classList.add('tall-grass-flip');
       container.appendChild(span);
     }
     this._rocks = [];