diff --git a/src/main.js b/src/main.js
index cbb4964..a182b62 100644
--- a/src/main.js
+++ b/src/main.js
@@ -422,7 +422,10 @@ class ForestScene extends Phaser.Scene {
         .setDepth(6);
 
       const surfaceWidth = (LOG_SURFACE_RIGHT - LOG_SURFACE_LEFT) * scale;
-      const surfaceCenterOffset = (
+      // The visible moss cap is biased left relative to the cropped log frame.
+      // Keep the corrected surface width, but mirror the centre correction so
+      // the collider follows the artwork rather than drifting right.
+      const surfaceCenterOffset = -(
         ((LOG_SURFACE_LEFT + LOG_SURFACE_RIGHT) / 2) - (LOG_FRAME_WIDTH / 2)
       ) * scale;