refactor: consolidate path rendering styles into shared PATH_STYLE constant

Move path band widths, colors, and groove properties out of ZumaGame
hardcoded constants and into a single PATH_STYLE config in ZumaLogic.
Both ZumaGame and ZumaEditor now draw the path using the same nested
band strokes for a consistent concave-channel appearance.

src/games/zuma/ZumaEditor.js

@@ -17,7 +17,7 @@ import { GAME_WIDTH, GAME_HEIGHT, COLORS } from '../../config.js';
 import { Button } from '../../ui/Button.js';
 import { playSound, SFX } from '../../ui/Sounds.js';
 import {
-  TUNING, BALL_COLORS, LEVEL_BOUNDS, buildPath, validateLevel, validateLevelParams,
+  TUNING, BALL_COLORS, LEVEL_BOUNDS, PATH_STYLE, buildPath, validateLevel, validateLevelParams,
 } from './ZumaLogic.js';
 
 const FONT = 'm6x11, "Julius Sans One"';
@@ -483,8 +483,7 @@ export default class ZumaEditor extends Phaser.Scene {
         }
         g.strokePath();
       };
-      stroke(80, 0x241b0e);
-      stroke(67, 0x4a3a26);
+      for (const { w, color } of PATH_STYLE.bands) stroke(w, color);
 
       // Ghost chain: the whole quota packed back from the hole — the shape of
       // the moment before you lose. Makes "does this path hold the marbles I

src/games/zuma/ZumaGame.js

@@ -5,12 +5,10 @@ import { MusicPlayer } from '../../ui/MusicPlayer.js';
 import { playSound, playScifiWoosh, playScifiExplode, SFX } from '../../ui/Sounds.js';
 import { api } from '../../services/api.js';
 import {
-  TUNING, BALL_COLORS, createLevel, step, fireBall, swapBalls, rayHit,
+  TUNING, BALL_COLORS, PATH_STYLE, createLevel, step, fireBall, swapBalls, rayHit,
 } from './ZumaLogic.js';
 
-const BG       = 0x0d1a10;          // deep jungle green
-const PATH_RIM = 0x241b0e;
-const PATH_BED = 0x4a3a26;
+const BG = 0x0d1a10;          // deep jungle green
 
 // The launcher is layered around the marble it holds: frog frame 0 sits under
 // the ready marble, frame 1 (the disc with the mouth slot cut out) sits over
@@ -44,9 +42,6 @@ const TUNE = {
   INSERT_MS: 120,        // squeeze-in tween for a landed shot
   POP_FX_MS: 320,        // particle burst lifetime
   LASER_ALPHA: 0.55,
-  PATH_W_RIM: 80,
-  PATH_W_BED: 67,
-  GROOVE_STEP: 48,       // px between center-groove dots
   NEXT_SCALE: 0.55,      // the on-deck marble shown in the frog's belly
 };
 
@@ -548,23 +543,21 @@ export default class ZumaGame extends Phaser.Scene {
   drawPath() {
     const samples = this.state.path.samples;
     const g = this.add.graphics().setDepth(D.path);
-    g.lineStyle(TUNE.PATH_W_RIM, PATH_RIM, 1);
-    g.beginPath();
-    g.moveTo(samples[0].x, samples[0].y);
-    for (const s of samples) g.lineTo(s.x, s.y);
-    g.strokePath();
-    g.lineStyle(TUNE.PATH_W_BED, PATH_BED, 1);
-    g.beginPath();
-    g.moveTo(samples[0].x, samples[0].y);
-    for (const s of samples) g.lineTo(s.x, s.y);
-    g.strokePath();
-    // dotted center groove
-    g.fillStyle(0x6b5638, 0.55);
+    for (const { w, color } of PATH_STYLE.bands) {
+      g.lineStyle(w, color, 1);
+      g.beginPath();
+      g.moveTo(samples[0].x, samples[0].y);
+      for (const s of samples) g.lineTo(s.x, s.y);
+      g.strokePath();
+    }
+    // dotted center groove — the seam the ball rolls along, sunk into the
+    // bright core band above
+    g.fillStyle(PATH_STYLE.grooveColor, PATH_STYLE.grooveAlpha);
     let nextDot = 0;
     for (const s of samples) {
       if (s.s >= nextDot) {
-        g.fillCircle(s.x, s.y, 4);
-        nextDot += TUNE.GROOVE_STEP;
+        g.fillCircle(s.x, s.y, PATH_STYLE.grooveRadius);
+        nextDot += PATH_STYLE.grooveStep;
       }
     }
     this.layer.add(g);

src/games/zuma/ZumaLogic.js

@@ -56,6 +56,29 @@ export const POWER_KINDS = ['slow', 'reverse', 'accuracy', 'explosion'];
 // first N of these. Lives here so the scene and the editor share one list.
 export const BALL_COLORS = [0xd9403a, 0xeec23d, 0x3f7fdb, 0x43b059, 0x9b59d0, 0xd9dde3];
 
+// The path is drawn as nested strokes on one centerline, widest first — each
+// narrower band paints over the middle of the last, leaving only its outer
+// edge showing as a ring. Ordered outer to inner it fakes a concave channel's
+// cross-section (dark contrast border -> lit embankment lip -> shadowed wall
+// -> the floor's own shadow/lit/core bands) with plain solid-color strokes,
+// no per-sample normals needed since the profile is symmetric across the
+// centerline. Shared by ZumaGame (draw) and ZumaEditor (preview, scaled by K).
+export const PATH_STYLE = {
+  bands: [
+    { w: 96, color: 0x0a0704 },   // outer contrast border, pops off any bg
+    { w: 84, color: 0x362615 },   // embankment lip catching light
+    { w: 80, color: 0x241b0e },   // embankment wall, in shadow
+    { w: 71, color: 0x2e2313 },   // shadow where the wall meets the floor
+    { w: 67, color: 0x4a3a26 },   // main floor
+    { w: 42, color: 0x6c5735 },   // floor lit by bounced light
+    { w: 20, color: 0x8f7a52 },   // pale core along the concave bottom
+  ],
+  grooveStep: 48,       // px between center-groove dots
+  grooveColor: 0x4a3a1f,
+  grooveAlpha: 0.4,
+  grooveRadius: 4,
+};
+
 // ── Seeded RNG (mulberry32, matches genRushHour.js) ─────────────────────────
 export function makeRng(seed) {
   let a = seed >>> 0;