Use a better constant for playfield positioning

osu.Game.Rulesets.Taiko/UI/TaikoPlayfieldAdjustmentContainer.cs

@@ -28,6 +28,8 @@ protected override void Update()
             base.Update();
 
             const float base_relative_height = TaikoPlayfield.BASE_HEIGHT / 768;
+            // Matches stable, see https://github.com/peppy/osu-stable-reference/blob/7519cafd1823f1879c0d9c991ba0e5c7fd3bfa02/osu!/GameModes/Play/Rulesets/Taiko/RulesetTaiko.cs#L514
+            const float base_position = 135f / 480f;
 
             float relativeHeight = base_relative_height;
 
@@ -49,14 +51,7 @@ protected override void Update()
             // Limit the maximum relative height of the playfield to one-third of available area to avoid it masking out on extreme resolutions.
             relativeHeight = Math.Min(relativeHeight, 1f / 3f);
 
-            // Position the taiko playfield exactly one playfield from the top of the screen, if there is enough space for it.
-            // Note that the relative height cannot exceed one-third - if that limit is hit, the playfield will be exactly centered.
-            float playfieldPosition = relativeHeight;
-
-            // arbitrary offset to make playfield position match stable.
-            playfieldPosition += 0.022f;
-
-            Y = playfieldPosition;
+            Y = base_position;
 
             Scale = new Vector2(Math.Max((Parent!.ChildSize.Y / 768f) * (relativeHeight / base_relative_height), 1f));
             Width = 1 / Scale.X;