diff --git a/.env.example b/.env.example
index cf53e48..2ac4e2a 100644
--- a/.env.example
+++ b/.env.example
@@ -1,2 +1,2 @@
 PORT=3000
-OPENROUTER_API_KEY=your_openrouter_api_key_here
+OPENROUTER_API_KEY=your-openrouter-api-key
diff --git a/README.md b/README.md
index f739a1a..2782aa7 100644
--- a/README.md
+++ b/README.md
@@ -27,24 +27,31 @@ Runs by default on `http://localhost:3000`.
 
 ## configuration
 
-The repo intentionally bundles an OpenRouter key (`REPO_API_KEY` in `server.js`, `worker.mjs` and
-`functions/api/ask.js`) so a fresh clone or a deploy works with nothing configured. Export
-`OPENROUTER_API_KEY` to override it — `GET /api/status` reports which key is live via `keySource`.
+jev8ball connects to OpenRouter to query the `typesafe/jev-1.13` decision oracle.
 
-```env
-PORT=3000
-OPENROUTER_API_KEY=sk-or-v1-...
-```
-
-Delete the `REPO_API_KEY` constants to require a configured key instead. For Cloudflare, store the
-override as a secret rather than a plain variable:
+1. Obtain an API key from [OpenRouter](https://openrouter.ai/keys).
+2. Configure your key via environment variables:
 
 ```bash
-wrangler secret put OPENROUTER_API_KEY
+# Local development: copy example env and set your key
+cp .env.example .env
+# Edit .env and set:
+OPENROUTER_API_KEY=sk-or-v1-your-key-here
 ```
 
-> The bundled key is readable by anyone who can read this repository, so treat it as public and
-> rotate or remove it before the repo is shared.
+```bash
+# Or export directly in shell
+export OPENROUTER_API_KEY="sk-or-v1-your-key-here"
+```
+
+For Cloudflare Pages / Workers deployment:
+- **Cloudflare Pages**: Add `OPENROUTER_API_KEY` under **Settings > Environment Variables** in the Pages dashboard.
+- **Cloudflare Workers**: Store it as an encrypted secret using Wrangler:
+```bash
+npx wrangler secret put OPENROUTER_API_KEY
+```
+
+> If no key is set or the default placeholder `your-openrouter-api-key` is left unchanged, jev8ball gracefully falls back to an offline deterministic oracle mode.
 
 ## endpoints
 
diff --git a/functions/api/ask.js b/functions/api/ask.js
index f50c3dd..58c6466 100644
--- a/functions/api/ask.js
+++ b/functions/api/ask.js
@@ -1,9 +1,8 @@
 const JEV_DECISIONS_URL = "https://openrouter.ai/api/alpha/decisions";
 const MODEL = "typesafe/jev-1.13";
 
-// Mirrors worker.mjs: the repo carries a key so a deploy works with no secret set.
-// Delete this constant and set OPENROUTER_API_KEY to require configuration.
-const REPO_API_KEY = "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";
+// Default placeholder API key. Set OPENROUTER_API_KEY in environment or Cloudflare secrets.
+const REPO_API_KEY = "your-openrouter-api-key";
 
 function resolveApiKey(env) {
   return env.OPENROUTER_API_KEY || REPO_API_KEY || null;
diff --git a/functions/api/status.js b/functions/api/status.js
index 18be857..3c4bcbe 100644
--- a/functions/api/status.js
+++ b/functions/api/status.js
@@ -1,6 +1,5 @@
-// Mirrors worker.mjs: the repo carries a key so a deploy works with no secret set.
-// Delete this constant and set OPENROUTER_API_KEY to require configuration.
-const REPO_API_KEY = "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";
+// Default placeholder API key. Set OPENROUTER_API_KEY in environment or Cloudflare secrets.
+const REPO_API_KEY = "your-openrouter-api-key";
 
 export async function onRequestGet(context) {
   const { env } = context;
diff --git a/public/js/ball3d.js b/public/js/ball3d.js
index bbe293c..6d6102e 100644
--- a/public/js/ball3d.js
+++ b/public/js/ball3d.js
@@ -16,6 +16,7 @@ import {
   dot,
   hexToRgb,
   lerp,
+  mat4FromQuat,
   mat4LookAt,
   mat4Mul,
   mat4Perspective,
@@ -25,7 +26,14 @@ import {
   mat4Translate,
   mixRgb,
   normalize,
+  oscillatorStep,
   projectToScreen,
+  quatError,
+  quatFromAxisAngle,
+  quatIdentity,
+  quatIntegrate,
+  quatMul,
+  quatRotate,
   rgbCss,
   smoothstep,
   transformDir,
@@ -35,13 +43,36 @@ import { createPlate, createVessel } from './meshes.js';
 
 const TAU = Math.PI * 2;
 const LIGHT = normalize([-0.42, 0.7, 0.86]);
-const VIEW = [0, 0, 1];
+
+/**
+ * Three-quarter camera. A dead-on view of a shallow prism is a flat silhouette; looking
+ * in from the side and slightly above keeps the bevelled rim, the tapered walls and the
+ * recessed chamber legible as depth.
+ */
+export const CAMERA = {
+  eye: [1.02, 0.66, 3.92],
+  target: [0, 0.02, 0],
+  fov: 36,
+  near: 0.1,
+  far: 40
+};
+
+/** Direction from the scene toward the camera: facing tests, rim light and specular. */
+const VIEW = normalize([
+  CAMERA.eye[0] - CAMERA.target[0],
+  CAMERA.eye[1] - CAMERA.target[1],
+  CAMERA.eye[2] - CAMERA.target[2]
+]);
 
 const BODY_BASE = hexToRgb('#191919');
 const BODY_EDGE = hexToRgb('#2b2b30');
 const CHAMBER_RGB = hexToRgb('#07070b');
 const PLATE_BASE = hexToRgb('#1b1b1f');
 const SPECULAR = [236, 245, 255];
+const FOG_RGB = hexToRgb('#0b0b0b');
+
+/** Depth haze: the back of the shell must sink into the page, not sit on top of it. */
+const FOG = { near: 3.55, far: 4.62, max: 0.3 };
 
 const TONES = {
   affirmative: hexToRgb('#10b981'),
@@ -57,6 +88,74 @@ const LIGHT_NEAR = normalize([LIGHT[0] - 0.35, LIGHT[1] + 0.32, LIGHT[2]]);
 const LIGHT_FAR = normalize([LIGHT[0] + 0.32, LIGHT[1] - 0.36, LIGHT[2]]);
 const FONT_STACK = "'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, Consolas, monospace";
 
+/**
+ * Die spin while the vessel is being shaken: a constant-speed tumble would look
+ * mechanical, so the angular velocity starts fast, decays with drag, and its axis slowly
+ * precesses — a body tumbling with angular momentum rather than an Euler loop.
+ */
+const SPIN = {
+  speed: 9.5,
+  spread: 3.6,
+  drag: 1.35,
+  precess: 0.85,
+  precessAxis: [0.25, 0.15, 1]
+};
+
+/**
+ * Die spring that unwinds the tumble onto the answer face. The error is expressed as a
+ * single angle about the shortest-path axis, so the die sweeps forward into the answer
+ * and bounces once (ζ < 1) — it can never rewind like the old linear unwind did.
+ */
+const SETTLE = {
+  omega: 10.5,
+  zeta: 0.68,
+  minRate: 2.5,
+  maxRate: 6.5,
+  landAngle: 0.16,
+  restAngle: 0.02
+};
+
+/** Hull rattle. Two incommensurate frequencies per channel stop it looking metronomic. */
+const SHAKE = {
+  attack: 0.055,
+  decay: 5.5,
+  x: [{ hz: 6.7, amp: 0.03 }, { hz: 10.9, amp: 0.013 }],
+  y: [{ hz: 5.3, amp: 0.042 }, { hz: 8.9, amp: 0.017 }],
+  yaw: [{ hz: 4.1, amp: 0.04 }, { hz: 7.7, amp: 0.015 }],
+  pitch: [{ hz: 4.9, amp: 0.048 }, { hz: 8.3, amp: 0.018 }],
+  roll: [{ hz: 3.7, amp: 0.055 }, { hz: 6.1, amp: 0.021 }]
+};
+
+const PLATE_SPRING = { omega: 24, zeta: 0.5 };
+const SURFACE_SPRING = { omega: 12, zeta: 0.2 };
+const THUMP_SPRING = { omega: 17, zeta: 0.18 };
+/** How hard the vessel's vertical motion throws the liquid surface around. */
+const SURFACE_COUPLING = 14;
+
+/** Deterministic [0,1) noise so every roll tumbles differently but reproducibly. */
+function seededUnit(seed) {
+  const x = Math.sin(seed * 12.9898) * 43758.5453;
+  return x - Math.floor(x);
+}
+
+/** Drives a position/velocity pair toward a moving target with a spring-damper. */
+export function springToward(state, target, dt, { omega, zeta }) {
+  const step = oscillatorStep({ x: state.x - target, v: state.v }, dt, omega, zeta);
+  return { x: target + step.x, v: step.v };
+}
+
+/**
+ * Sum of incommensurate sines — a rattle that never repeats on a short cycle. The caller
+ * scales it by a continuously varying envelope, so it stays smooth through every phase
+ * change.
+ */
+function rattle(clock, channels) {
+  let sum = 0;
+  for (const { hz, amp } of channels) sum += Math.sin(TAU * hz * clock + hz) * amp;
+  return sum;
+}
+
+
 /** Phases: rolling -> (answer arrives) -> revealing -> ready -> idle. */
 export class OracleBall {
   constructor(canvas, { reducedMotion = false } = {}) {
@@ -81,17 +180,32 @@ export class OracleBall {
     this.revealStart = 0;
     this.holdTime = 0;
     this.rollDuration = 1.25;
-    this.revealDuration = 0.9;
+    this.revealDuration = 1.1;
+    this.rollProgress = 0;
+    this.rollCount = 0;
 
     this.answerLines = ['CONCENTRATE', '& ASK'];
     this.tone = 'idle';
     this.pendingAnswer = null;
+    this.answerAlpha = 1;
 
     this.pointer = { x: 0, y: 0 };
     this.tilt = { x: 0, y: 0 };
-    this.shake = 0;
     this.glow = 0;
     this.resolveRoll = null;
+
+    // Die: a free tumble that a spring later unwinds onto the answer face.
+    this.plateQuat = quatIdentity();
+    this.spin = { q: quatIdentity(), w: [0, 0, 0] };
+    this.settle = null;
+    this.landed = true;
+    this.plateY = { x: 0.02, v: 0 };
+
+    // Hull rattle, impact bounce and the chamber liquid, all spring-driven.
+    this.shakeEnergy = 0;
+    this.hull = { x: 0, y: 0, yaw: 0, pitch: 0, roll: 0 };
+    this.thump = { x: 0, v: 0 };
+    this.surface = { x: 0, v: 0 };
   }
 
   /* ─── public API ─── */
@@ -127,8 +241,26 @@ export class OracleBall {
     this.phase = 'rolling';
     this.rollStart = this.clock;
     this.holdTime = 0;
+    this.rollProgress = 0;
     this.glow = 0;
     this.answerLines = null;
+    this.answerAlpha = 0;
+    this.settle = null;
+    this.landed = false;
+    this.rollCount += 1;
+
+    // Kick the die into a fresh tumble: fast, off-axis, and never quite the same twice.
+    const seed = this.rollCount * 7.13;
+    const axis = normalize([
+      0.7 + seededUnit(seed) * 0.6,
+      0.4 + seededUnit(seed + 1.7) * 0.7,
+      0.15 + seededUnit(seed + 3.1) * 0.45
+    ]);
+    const speed = SPIN.speed + seededUnit(seed + 5.3) * SPIN.spread;
+    this.spin.q = this.plateQuat;
+    this.spin.w = [axis[0] * speed, axis[1] * speed, axis[2] * speed];
+    this.shakeEnergy = 0;
+
     return new Promise((resolve) => {
       // Backstop so a paused render loop (hidden tab, off-screen canvas) can never
       // leave the caller waiting forever.
@@ -149,8 +281,9 @@ export class OracleBall {
     this.answerLines = lines;
     this.tone = tone;
     this.revealStart = this.clock;
-    this.tumbleAtReveal = this.platePose ? { ...this.platePose } : { rx: 0, ry: 0, rz: 0, y: -0.5 };
+    this.landed = false;
     this.phase = 'revealing';
+    this._beginSettle();
   }
 
   /** Returns the vessel to the resting state and clears the verdict. */
@@ -160,6 +293,11 @@ export class OracleBall {
     this.phase = 'idle';
     this.glow = 0;
     this.pendingAnswer = null;
+    this.settle = null;
+    this.landed = true;
+    this.answerAlpha = 1;
+    this.plateQuat = quatIdentity();
+    this.spin.w = [0, 0, 0];
   }
 
   /* ─── wiring ─── */
@@ -221,18 +359,49 @@ export class OracleBall {
   };
 
   _update(dt) {
+    const rm = this.reducedMotion;
     const ease = Math.min(1, dt * 6);
-    this.tilt.x += ((this.reducedMotion ? 0 : this.pointer.y * 0.2) - this.tilt.x) * ease;
-    this.tilt.y += ((this.reducedMotion ? 0 : this.pointer.x * 0.3) - this.tilt.y) * ease;
+    this.tilt.x += ((rm ? 0 : this.pointer.y * 0.24) - this.tilt.x) * ease;
+    this.tilt.y += ((rm ? 0 : this.pointer.x * 0.34) - this.tilt.y) * ease;
 
     const elapsed = this.clock - this.rollStart;
 
+    // ─── hull rattle ───
+    // One continuously varying envelope drives every channel, so the shake can start and
+    // stop with the phase machine without ever teleporting the vessel.
+    if (this.phase === 'rolling' && !rm) {
+      this.shakeEnergy = Math.min(1, this.shakeEnergy + dt / SHAKE.attack);
+    } else {
+      this.shakeEnergy *= Math.exp(-dt * SHAKE.decay);
+      if (this.shakeEnergy < 1e-4) this.shakeEnergy = 0;
+    }
+    const energy = this.shakeEnergy;
+    this.hull = {
+      x: rattle(this.clock, SHAKE.x) * energy,
+      y: rattle(this.clock, SHAKE.y) * energy,
+      yaw: rattle(this.clock, SHAKE.yaw) * energy,
+      pitch: rattle(this.clock, SHAKE.pitch) * energy,
+      roll: rattle(this.clock, SHAKE.roll) * energy
+    };
+    this.thump = oscillatorStep(this.thump, dt, THUMP_SPRING.omega, THUMP_SPRING.zeta);
+
+    let targetY = 0.02;
+
     if (this.phase === 'rolling') {
-      this.rollProgress = this.reducedMotion ? 1 : clamp(elapsed / this.rollDuration, 0, 1);
-      this.shake = this.reducedMotion
-        ? 0
-        : (1 - this.rollProgress * 0.6) * Math.sin(elapsed * 24) * 0.42;
-      this.liquidSlosh = this.reducedMotion ? 0 : 1;
+      this.rollProgress = rm ? 1 : clamp(elapsed / this.rollDuration, 0, 1);
+      if (rm) {
+        this.plateQuat = quatFromAxisAngle([0.6, 0.75, 0.25], 0.5);
+      } else {
+        // Angular momentum: the spin decays with drag while its axis precesses, which is
+        // what separates a tumbling body from a constant-speed Euler loop.
+        const drag = Math.exp(-SPIN.drag * dt);
+        this.spin.w = quatRotate(
+          quatFromAxisAngle(SPIN.precessAxis, SPIN.precess * dt),
+          [this.spin.w[0] * drag, this.spin.w[1] * drag, this.spin.w[2] * drag]
+        );
+        this.spin.q = quatIntegrate(this.spin.q, this.spin.w, dt);
+        this.plateQuat = this.spin.q;
+      }
       if (elapsed >= this.rollDuration) {
         this.holdTime += dt;
         if (this.resolveRoll) {
@@ -241,51 +410,87 @@ export class OracleBall {
           resolve();
         }
       }
-      this.platePose = this._tumblePose(elapsed);
+      targetY = -0.3 + 0.07 * energy * Math.sin(TAU * 5.1 * this.clock);
       this.answerAlpha = 0;
-      this.glow = this.reducedMotion ? 0 : 0.12 + Math.sin(elapsed * 9) * 0.06;
+      this.glow = rm ? 0.1 : 0.1 + energy * 0.07;
     } else if (this.phase === 'revealing') {
-      const t = this.reducedMotion ? 1 : clamp((this.clock - this.revealStart) / this.revealDuration, 0, 1);
-      const settle = smoothstep(0, 0.72, t);
-      const from = this.tumbleAtReveal || { rx: 0, ry: 0, rz: 0, y: -0.5 };
-      // Unwind the tumble to zero so the plate always lands face-on to the camera.
-      this.platePose = {
-        rx: from.rx * (1 - settle),
-        ry: from.ry * (1 - settle),
-        rz: from.rz * (1 - settle),
-        y: lerp(from.y, 0.06, settle)
-      };
-      this.shake = this.reducedMotion ? 0 : (1 - t) * Math.sin(t * 18) * 0.12;
-      this.liquidSlosh = this.reducedMotion ? 0 : 1 - t;
-      this.answerAlpha = smoothstep(0.5, 1, t);
-      this.glow = Math.sin(t * Math.PI) * 1.1 + 0.16;
-      if (t >= 1) this.phase = 'ready';
+      if (!this.settle) this._beginSettle();
+      if (rm) this.settle.angle = { x: 0, v: 0 };
+      this.settle.angle = oscillatorStep(this.settle.angle, dt, SETTLE.omega, SETTLE.zeta);
+      this.plateQuat = quatMul(
+        quatFromAxisAngle(this.settle.axis, this.settle.angle.x),
+        this.settle.target
+      );
+
+      // The spring unwinds the whole error along the shortest path, so the die sweeps
+      // *into* the answer and rocks once past it — never rewinding the tumble.
+      const remaining = Math.abs(this.settle.angle.x);
+      if (!this.landed && remaining <= SETTLE.landAngle) {
+        this.landed = true;
+        this.thump.v -= rm ? 2 : 7.5; // the hull takes the impact…
+        this.plateY.v -= 1; // …and the die sinks into the liquid
+        this.surface.v += 2.4;
+        this.glow = Math.max(this.glow, 0.9);
+      }
+      // The ink fades in as the face turns toward the camera, and is latched so the small
+      // overshoot of the settle can never make the verdict flicker.
+      this.answerAlpha = Math.max(
+        this.answerAlpha,
+        smoothstep(SETTLE.landAngle * 3, SETTLE.restAngle * 3.5, remaining)
+      );
+      targetY = 0.06;
+      const settled =
+        remaining <= SETTLE.restAngle && Math.abs(this.settle.angle.v) <= 0.25;
+      if (settled || this.clock - this.revealStart > this.revealDuration * 2) {
+        this.phase = 'ready';
+      }
     } else {
-      const bob = this.reducedMotion ? 0 : Math.sin(this.clock * 1.15) * 0.022;
-      this.platePose = {
-        rx: this.reducedMotion ? 0 : Math.sin(this.clock * 0.42) * 0.06,
-        ry: this.reducedMotion ? 0 : Math.sin(this.clock * 0.55) * 0.24,
-        rz: this.reducedMotion ? 0 : Math.sin(this.clock * 0.37) * 0.05,
-        y: 0.02 + bob
-      };
-      this.liquidSlosh = this.reducedMotion ? 0 : 0.25;
+      // ready / idle: square to the camera with only a whisper of movement, so the verdict
+      // stays readable instead of rocking under the reader's eye.
+      const wobble = rm ? 0 : 1;
+      this.plateQuat = quatMul(
+        quatFromAxisAngle([0, 1, 0], Math.sin(this.clock * 0.62) * 0.03 * wobble),
+        quatFromAxisAngle([1, 0, 0], Math.sin(this.clock * 0.47) * 0.024 * wobble)
+      );
+      const bob = rm ? 0 : Math.sin(this.clock * 1.15) * 0.022;
+      targetY = 0.02 + bob;
       this.answerAlpha = this.answerLines ? 1 : 0;
       this.glow = this.phase === 'ready' ? 0.16 + Math.sin(this.clock * 1.6) * 0.04 : 0.06;
     }
+
+    this.plateY = springToward(this.plateY, targetY, dt, PLATE_SPRING);
+
+    // ─── chamber liquid ───
+    // The surface is an oscillator kicked by the vessel's own vertical motion, so it
+    // sloshes while the oracle is shaken, splashes when the die lands and settles still —
+    // instead of the old sine that wobbled forever.
+    const hullY = this.hull.y + this.thump.x;
+    const hullFall = this.prevHullY === undefined ? 0 : hullY - this.prevHullY;
+    this.prevHullY = hullY;
+    this.surface.v -= hullFall * SURFACE_COUPLING;
+    this.surface = oscillatorStep(this.surface, dt, SURFACE_SPRING.omega, SURFACE_SPRING.zeta);
   }
 
-  /** Churning pose used while the vessel is being shaken. */
-  _tumblePose(elapsed) {
-    const dive = smoothstep(0, this.rollDuration * 0.85, elapsed);
-    if (this.reducedMotion) {
-      return { rx: 0.5, ry: 0.6, rz: 0.2, y: lerp(0.02, -0.24, dive) };
-    }
-    return {
-      rx: elapsed * 5.2,
-      ry: elapsed * 3.05,
-      rz: elapsed * 2.15,
-      y: lerp(0.02, -0.5, dive)
+  /**
+   * Captures the tumble's remaining error as one angle about its shortest-path axis, and
+   * hands the spring the die's current spin so the settle starts without a jolt.
+   */
+  _beginSettle(from = this.spin.q) {
+    const error = quatError(from, quatIdentity());
+    // Only the spin component *about the settle axis* carries into the unwind; the rest of
+    // the tumble's momentum is orthogonal and must not be added as fake approach speed. The
+    // ceiling keeps a fast tumble from snapping the die round in a couple of frames.
+    const rate = clamp(
+      dot(this.spin.w, error.axis),
+      SETTLE.minRate,
+      SETTLE.maxRate
+    );
+    this.settle = {
+      axis: error.axis,
+      angle: { x: error.angle, v: -rate },
+      target: quatIdentity()
     };
+    this.plateQuat = from;
   }
 
   get toneRgb() {
@@ -303,24 +508,29 @@ export class OracleBall {
     ctx.clearRect(0, 0, this.canvas.width, this.canvas.height);
     ctx.setTransform(this.dpr, 0, 0, this.dpr, 0, 0);
 
-    // Camera sits far enough that the vessel fills ~72% of the canvas height,
-    // leaving room for the shake, the rim glow, and the cast shadow.
-    const view = mat4LookAt([0, 0, 4.3], [0, 0, 0], [0, 1, 0]);
-    const proj = mat4Perspective((36 * Math.PI) / 180, 1, 0.1, 40);
+    // The camera frames the vessel at ~72% of the canvas height, leaving room for the
+    // rattle, the rim glow and the cast shadow.
+    const view = mat4LookAt(CAMERA.eye, CAMERA.target, [0, 1, 0]);
+    const proj = mat4Perspective((CAMERA.fov * Math.PI) / 180, 1, CAMERA.near, CAMERA.far);
     this.viewProj = mat4Mul(proj, view);
 
-    const pose = this.platePose || { rx: 0, ry: 0, rz: 0, y: 0.02 };
-    const shakeZ = this.shake * 0.5;
-    const vesselModel = mat4Mul(
-      mat4RotateZ(shakeZ),
+    // Hull: pointer parallax plus the rattle, with the impact bounce folded into y.
+    const hullRot = mat4Mul(
+      mat4RotateZ(this.hull.roll),
       mat4Mul(
-        mat4RotateY(this.tilt.y + this.shake * 0.28),
-        mat4RotateX(this.tilt.x + Math.cos(this.clock * 9) * this.shake * 0.22)
+        mat4RotateY(this.tilt.y + this.hull.yaw),
+        mat4RotateX(this.tilt.x + this.hull.pitch)
       )
     );
+    const vesselModel = mat4Mul(
+      mat4Translate(this.hull.x, this.hull.y + this.thump.x, 0),
+      hullRot
+    );
+    // The die rides inside the hull, so parallax and shake carry it along instead of
+    // letting it look pasted onto the screen.
     const plateModel = mat4Mul(
-      mat4Translate(0, pose.y, 0),
-      mat4Mul(mat4RotateZ(pose.rz), mat4Mul(mat4RotateY(pose.ry), mat4RotateX(pose.rx)))
+      hullRot,
+      mat4Mul(mat4Translate(0, this.plateY.x, 0), mat4FromQuat(this.plateQuat))
     );
 
     this._drawGroundGlow(w, h);
@@ -335,9 +545,9 @@ export class OracleBall {
 
     const tone = this.toneRgb;
 
-    // 1. shell behind the chamber: back cap first, then the side facets
+    // 1. shell behind the chamber: the back cap, then the tapered side walls
     for (const face of vessel.faces) {
-      if (face.kind === 'ring') continue;
+      if (face.kind === 'ring' || face.kind === 'bevel') continue;
       const base = face.kind === 'back' ? CHAMBER_RGB : BODY_BASE;
       this._fillFace(face, this._faceStyle(face, base, tone, face.kind === 'back' ? 0.05 : 0.55));
     }
@@ -352,16 +562,18 @@ export class OracleBall {
         this._fillFace(face, this._faceStyle(face, base, tone, face.kind === 'answer' ? 0.35 : 0.8));
       }
       if (this.answerLines && this.answerAlpha > 0.01) {
-        this._drawAnswerText(plate, windowPoly);
+        this._drawAnswerText(plate);
       }
       this._overlayLiquid(liquid, tone);
       ctx.restore();
     }
 
-    // 3. the front frame, nearest to the camera, drawn last
+    // 3. the front of the shell, drawn last: the forward-facing bevel carries the key
+    //    light and the flat collar sits just behind it.
     for (const face of vessel.faces) {
-      if (face.kind !== 'ring') continue;
-      this._fillFace(face, this._faceStyle(face, BODY_EDGE, tone, 0.5));
+      if (face.kind !== 'ring' && face.kind !== 'bevel') continue;
+      const base = face.kind === 'bevel' ? BODY_EDGE : BODY_BASE;
+      this._fillFace(face, this._faceStyle(face, base, tone, face.kind === 'bevel' ? 0.3 : 0.5));
     }
 
     if (windowPoly) this._strokeWindow(windowPoly, tone);
@@ -408,9 +620,10 @@ export class OracleBall {
   _liquidGeometry(vesselModel, windowPoly) {
     const mvp = mat4Mul(this.viewProj, vesselModel);
     const { radius, z } = this.vessel.window;
-    const slosh = this.liquidSlosh || 0;
-    const level = -0.09 + Math.sin(this.clock * 8.5) * 0.05 * slosh;
-    const tilt = Math.sin(this.clock * 6.3) * 0.16 * slosh;
+    // Level and tilt come from the slosh oscillator, so the surface rings down to a still
+    // mirror once the oracle settles instead of waving forever.
+    const level = -0.075 + this.surface.x;
+    const tilt = clamp(this.surface.v * 0.03, -0.2, 0.2);
     const left = projectToScreen(
       transformPoint(mvp, [-radius * 1.35, level + tilt, z * 0.2]),
       this.width,
@@ -441,13 +654,16 @@ export class OracleBall {
 
   _drawContactShadow(w, h) {
     const { ctx } = this;
-    const lift = (this.platePose ? 0 : 0) + 0.02;
+    // The shadow stays anchored while the hull rattles above it, which is what sells the
+    // vessel as a solid body in front of a surface rather than a flat image being nudged.
+    const spread = 1 + this.shakeEnergy * 0.22;
+    const opacity = 0.6 - this.shakeEnergy * 0.16;
     ctx.save();
-    ctx.translate(w / 2, h * 0.5 + h * 0.4 + lift);
+    ctx.translate(w / 2, h * 0.5 + h * 0.4);
     ctx.scale(1, 0.2);
-    const radius = w * 0.31;
+    const radius = w * 0.31 * spread;
     const gradient = ctx.createRadialGradient(0, 0, 0, 0, 0, radius);
-    gradient.addColorStop(0, 'rgba(0,0,0,0.6)');
+    gradient.addColorStop(0, `rgba(0,0,0,${opacity})`);
     gradient.addColorStop(1, 'rgba(0,0,0,0)');
     ctx.beginPath();
     ctx.arc(0, 0, radius, 0, TAU);
@@ -458,28 +674,30 @@ export class OracleBall {
 
   /* ─── shading & paint helpers ─── */
 
-  /** Blinn-Phong-ish shade: ambient + Lambert, specular, and a verdict-tinted rim. */
-  _shade(base, normal, light, tone, rimStrength) {
+  /** Blinn-Phong-ish shade: ambient + Lambert, specular, a verdict rim and depth haze. */
+  _shade(base, normal, light, tone, rimStrength, fog = 0) {
     const diffuse = Math.max(0, dot(normal, light));
-    const half = normalize([light[0], light[1], light[2] + 1]);
-    const spec = Math.pow(Math.max(0, dot(normal, half)), 40) * 0.5;
+    const half = normalize([light[0] + VIEW[0], light[1] + VIEW[1], light[2] + VIEW[2]]);
+    const spec = Math.pow(Math.max(0, dot(normal, half)), 42) * 0.55;
     const rim = Math.pow(1 - clamp(dot(normal, VIEW), 0, 1), 3) * rimStrength;
-    const lit = 0.13 + diffuse * 0.95;
+    const lit = 0.12 + diffuse * 0.95;
     const rgb = [
       base[0] * lit + SPECULAR[0] * spec,
       base[1] * lit + SPECULAR[1] * spec,
       base[2] * lit + SPECULAR[2] * spec
     ];
-    return mixRgb(rgb, tone, clamp(rim * 0.55, 0, 1));
+    const tinted = mixRgb(rgb, tone, clamp(rim * 0.55, 0, 1));
+    return fog > 0 ? mixRgb(tinted, FOG_RGB, fog) : tinted;
   }
 
   /** Solid fill for faceted faces, soft gradient for the large curved ones. */
   _faceStyle(face, base, tone, rimStrength) {
+    const fog = smoothstep(FOG.near, FOG.far, face.depth) * FOG.max;
     if (!face.smooth) {
-      return rgbCss(this._shade(base, face.normal, LIGHT, tone, rimStrength));
+      return rgbCss(this._shade(base, face.normal, LIGHT, tone, rimStrength, fog));
     }
-    const near = this._shade(base, face.normal, LIGHT_NEAR, tone, rimStrength);
-    const far = this._shade(base, face.normal, LIGHT_FAR, tone, rimStrength);
+    const near = this._shade(base, face.normal, LIGHT_NEAR, tone, rimStrength, fog);
+    const far = this._shade(base, face.normal, LIGHT_FAR, tone, rimStrength, fog);
     const bounds = boundsOf(face.points);
     const gradient = this.ctx.createLinearGradient(bounds.minX, bounds.minY, bounds.maxX, bounds.maxY);
     gradient.addColorStop(0, rgbCss(mixRgb(near, SPECULAR, 0.05)));
diff --git a/public/js/math3d.js b/public/js/math3d.js
index 3fbecb5..4b33b21 100644
--- a/public/js/math3d.js
+++ b/public/js/math3d.js
@@ -219,6 +219,146 @@ export function affineFromThreePoints(p1, p2, p3) {
   return [a, b, c, d, s1[0] - a * x1 - c * y1, s1[1] - b * x1 - d * y1];
 }
 
+/* ─── quaternions ([x, y, z, w], same right-handed convention as the matrices) ─── */
+
+export function quatIdentity() {
+  return [0, 0, 0, 1];
+}
+
+export function quatFromAxisAngle(axis, rad) {
+  const n = normalize(axis);
+  const half = rad / 2;
+  const s = Math.sin(half);
+  return [n[0] * s, n[1] * s, n[2] * s, Math.cos(half)];
+}
+
+/** Returns a ∘ b (b applied first). */
+export function quatMul(a, b) {
+  const [ax, ay, az, aw] = a;
+  const [bx, by, bz, bw] = b;
+  return [
+    aw * bx + ax * bw + ay * bz - az * by,
+    aw * by - ax * bz + ay * bw + az * bx,
+    aw * bz + ax * by - ay * bx + az * bw,
+    aw * bw - ax * bx - ay * by - az * bz
+  ];
+}
+
+export function quatConjugate(q) {
+  return [-q[0], -q[1], -q[2], q[3]];
+}
+
+export function quatDot(a, b) {
+  return a[0] * b[0] + a[1] * b[1] + a[2] * b[2] + a[3] * b[3];
+}
+
+export function quatNormalize(q) {
+  const len = Math.hypot(q[0], q[1], q[2], q[3]);
+  return len === 0 ? quatIdentity() : [q[0] / len, q[1] / len, q[2] / len, q[3] / len];
+}
+
+/** Shortest-path spherical interpolation; falls back to a lerp when nearly parallel. */
+export function quatSlerp(a, b, t) {
+  let d = quatDot(a, b);
+  let target = b;
+  if (d < 0) {
+    target = [-b[0], -b[1], -b[2], -b[3]];
+    d = -d;
+  }
+  if (d > 0.9995) {
+    return quatNormalize([
+      a[0] + (target[0] - a[0]) * t,
+      a[1] + (target[1] - a[1]) * t,
+      a[2] + (target[2] - a[2]) * t,
+      a[3] + (target[3] - a[3]) * t
+    ]);
+  }
+  const theta = Math.acos(clamp(d, -1, 1));
+  const sinTheta = Math.sin(theta);
+  const wa = Math.sin((1 - t) * theta) / sinTheta;
+  const wb = Math.sin(t * theta) / sinTheta;
+  return quatNormalize([
+    a[0] * wa + target[0] * wb,
+    a[1] * wa + target[1] * wb,
+    a[2] * wa + target[2] * wb,
+    a[3] * wa + target[3] * wb
+  ]);
+}
+
+/**
+ * Shortest-path rotation taking `from` onto `to`: the axis (unit, world space) and the
+ * angle in [0, π]. `quatMul(quatFromAxisAngle(axis, angle), to)` reproduces `from`,
+ * which is what lets a spring unwind the remaining error without ever rewinding.
+ */
+export function quatError(from, to) {
+  // The rotation takes `to` onto `from`, so it can be *unwound*: pre-multiplying `to` by
+  // the returned axis/angle reproduces `from`, and driving the angle to zero lands on `to`.
+  let d = quatMul(from, quatConjugate(to));
+  if (d[3] < 0) d = [-d[0], -d[1], -d[2], -d[3]];
+  const v = [d[0], d[1], d[2]];
+  const sin = Math.hypot(v[0], v[1], v[2]);
+  return {
+    axis: sin < 1e-9 ? [0, 1, 0] : [v[0] / sin, v[1] / sin, v[2] / sin],
+    angle: 2 * Math.atan2(sin, d[3])
+  };
+}
+
+/** Integrates a freely spinning body one step: q' = normalize(q + ½ ω q dt). */
+export function quatIntegrate(q, omega, dt) {
+  const spin = [omega[0] * 0.5 * dt, omega[1] * 0.5 * dt, omega[2] * 0.5 * dt, 0];
+  const dq = quatMul(spin, q);
+  return quatNormalize([q[0] + dq[0], q[1] + dq[1], q[2] + dq[2], q[3] + dq[3]]);
+}
+
+/** Rotates a direction by a unit quaternion. */
+export function quatRotate(q, v) {
+  const qv = [q[0], q[1], q[2]];
+  const t = mulScalar(cross(qv, v), 2);
+  return add(add(v, mulScalar(t, q[3])), cross(qv, t));
+}
+
+/** Column-major Float32Array(16) for a unit quaternion. */
+export function mat4FromQuat(q) {
+  const [x, y, z, w] = q;
+  const m = mat4Identity();
+  m[0] = 1 - 2 * (y * y + z * z);
+  m[1] = 2 * (x * y + z * w);
+  m[2] = 2 * (x * z - y * w);
+  m[4] = 2 * (x * y - z * w);
+  m[5] = 1 - 2 * (x * x + z * z);
+  m[6] = 2 * (y * z + x * w);
+  m[8] = 2 * (x * z + y * w);
+  m[9] = 2 * (y * z - x * w);
+  m[10] = 1 - 2 * (x * x + y * y);
+  return m;
+}
+
+/** Integration quantum for `oscillatorStep`: exact for frame times that are multiples of it. */
+export const OSCILLATOR_SUBSTEP = 1 / 240;
+
+/**
+ * One step of a damped harmonic oscillator, integrated with fixed sub-steps so the result
+ * does not depend on the frame time and cannot blow up on a slow frame (the explicit
+ * scheme is only stable while ω·h stays well below 2).
+ *
+ * @param {{x: number, v: number}} state position and velocity
+ * @param {number} dt frame time in seconds
+ * @param {number} omega undamped angular frequency (rad/s)
+ * @param {number} zeta damping ratio (1 = critically damped, < 1 overshoots)
+ */
+export function oscillatorStep(state, dt, omega, zeta, substep = OSCILLATOR_SUBSTEP) {
+  let { x, v } = state;
+  let remaining = dt;
+  while (remaining > 1e-9) {
+    const h = Math.min(substep, remaining);
+    remaining -= h;
+    const accel = -omega * omega * x - 2 * zeta * omega * v;
+    v += accel * h;
+    x += v * h;
+  }
+  return { x, v };
+}
+
 /** Mixes two [r, g, b] colours (0..255) by t. */
 export function mixRgb(from, to, t) {
   return [
diff --git a/public/js/meshes.js b/public/js/meshes.js
index 46a808a..5aa8c21 100644
--- a/public/js/meshes.js
+++ b/public/js/meshes.js
@@ -2,8 +2,14 @@
  * Mesh builders for the oracle vessel. Pure data in, pure data out: every mesh is
  * `{ vertices: [[x, y, z]], faces: [{ indices, normal, kind, smooth }] }`, which the
  * renderer walks generically.
+ *
+ * Both solids are stacks of hexagonal rings, which lets a bevel sit wherever an edge
+ * should catch the key light. At the camera's three-quarter angle those bevels are what
+ * make the shapes read as solid rather than as flat silhouettes.
  */
 
+import { normalize } from './math3d.js';
+
 /** Point-up hexagon vertices (matches the CSS clip-path used elsewhere). */
 export function hexagon(radius, rotation = Math.PI / 2) {
   return Array.from({ length: 6 }, (_, i) => {
@@ -25,19 +31,57 @@ function centroid(vertices, indices) {
 }
 
 /**
- * The outer shell: a hexagonal prism whose front cap has a hexagonal opening so the
- * liquid chamber inside is visible through the frame.
+ * Outward normal of a wall, solved in the (radius, z) profile plane. Both solids are
+ * surfaces of revolution about the z axis, so "outward" is simply the sign that points
+ * away from the interior at (0, 0) — no hand-picked normals to get wrong when a ring
+ * moves.
  */
-export function createVessel({ outerRadius = 1, depth = 0.52, windowRadius = 0.63 } = {}) {
-  const half = depth / 2;
-  const inner = hexagon(windowRadius);
+function profileNormal(u1, z1, u2, z2) {
+  let nu = z2 - z1;
+  let nz = -(u2 - u1);
+  if (-u1 * nu - z1 * nz > 0) {
+    nu = -nu;
+    nz = -nz;
+  }
+  const len = Math.hypot(nu, nz) || 1;
+  return [nu / len, nz / len];
+}
+
+/** Lifts a profile normal into a 3D face normal for the wall facing `angle`. */
+function wallNormal(angle, profile) {
+  return [Math.cos(angle) * profile[0], Math.sin(angle) * profile[0], profile[1]];
+}
+
+/** Mid-angle of the hexagonal wall between vertex i and i + 1. */
+const wallAngle = (i) => Math.PI / 2 + ((i + 0.5) * Math.PI) / 3;
+
+/**
+ * The outer shell: a chamfered hexagonal puck.
+ *
+ * The widest ring sits *behind* the front plane, so a bevel slopes forward and outward
+ * from it to the flat front cap — that bevel faces the camera and the key light, which is
+ * what gives the body its solid read. The front cap carries the recessed window.
+ */
+export function createVessel({
+  radius = 1,
+  rimZ = 0.24,
+  frontRadius = 0.88,
+  frontZ = 0.37,
+  backRadius = 0.8,
+  backZ = -0.37,
+  windowRadius = 0.63
+} = {}) {
   const vertices = [];
   const push = (x, y, z) => vertices.push([x, y, z]) - 1;
-  const points = hexagon(outerRadius);
+  const ring = (r, z) => hexagon(r).map(([x, y]) => push(x, y, z));
 
-  const outerBack = points.map(([x, y]) => push(x, y, -half));
-  const outerFront = points.map(([x, y]) => push(x, y, half));
-  const innerFront = inner.map(([x, y]) => push(x, y, half));
+  const outerBack = ring(backRadius, backZ);
+  const rim = ring(radius, rimZ);
+  const outerFront = ring(frontRadius, frontZ);
+  const innerFront = ring(windowRadius, frontZ);
+
+  const side = profileNormal(backRadius, backZ, radius, rimZ);
+  const bevel = profileNormal(radius, rimZ, frontRadius, frontZ);
 
   const faces = [
     { indices: [...outerBack].reverse(), normal: [0, 0, -1], kind: 'back', smooth: true }
@@ -45,13 +89,19 @@ export function createVessel({ outerRadius = 1, depth = 0.52, windowRadius = 0.6
 
   for (let i = 0; i < 6; i += 1) {
     const j = (i + 1) % 6;
-    const mid = Math.PI / 2 + ((i + 0.5) * Math.PI) / 3;
+    const angle = wallAngle(i);
     faces.push({
-      indices: [outerBack[i], outerBack[j], outerFront[j], outerFront[i]],
-      normal: [Math.cos(mid), Math.sin(mid), 0],
+      indices: [outerBack[i], outerBack[j], rim[j], rim[i]],
+      normal: wallNormal(angle, side),
       kind: 'side',
       smooth: true
     });
+    faces.push({
+      indices: [rim[i], rim[j], outerFront[j], outerFront[i]],
+      normal: wallNormal(angle, bevel),
+      kind: 'bevel',
+      smooth: false
+    });
     faces.push({
       indices: [outerFront[i], outerFront[j], innerFront[j], innerFront[i]],
       normal: [0, 0, 1],
@@ -62,20 +112,33 @@ export function createVessel({ outerRadius = 1, depth = 0.52, windowRadius = 0.6
 
   return {
     mesh: { vertices, faces },
-    window: { radius: windowRadius, z: half, points: inner },
-    extents: { outerRadius, depth, windowRadius }
+    window: { radius: windowRadius, z: frontZ, points: hexagon(windowRadius) },
+    extents: { radius, rimZ, frontRadius, frontZ, backRadius, backZ, windowRadius }
   };
 }
 
-/** The floating die: a flat hexagonal plate that can settle face-on to the answer. */
-export function createPlate({ radius = 0.44, thickness = 0.16 } = {}) {
+/**
+ * The floating die: a chamfered hexagonal token. The front face stays flat (the verdict is
+ * inked onto it), while the bevelled shoulder and rim give the tumble a moving highlight
+ * instead of a flat edge-on line.
+ */
+export function createPlate({ radius = 0.44, thickness = 0.2, chamfer = 0.05 } = {}) {
   const half = thickness / 2;
-  const points = hexagon(radius);
+  const lipZ = half - chamfer * 1.6;
+  const faceRadius = radius - chamfer;
+
   const vertices = [];
   const push = (x, y, z) => vertices.push([x, y, z]) - 1;
+  const ring = (r, z) => hexagon(r).map(([x, y]) => push(x, y, z));
 
-  const front = points.map(([x, y]) => push(x, y, half));
-  const back = points.map(([x, y]) => push(x, y, -half));
+  const front = ring(faceRadius, half);
+  const frontLip = ring(radius, lipZ);
+  const backLip = ring(radius, -lipZ);
+  const back = ring(faceRadius, -half);
+
+  const shoulder = profileNormal(radius, lipZ, faceRadius, half);
+  const rim = profileNormal(radius, -lipZ, radius, lipZ);
+  const heel = profileNormal(faceRadius, -half, radius, -lipZ);
 
   const faces = [
     { indices: front, normal: [0, 0, 1], kind: 'answer', smooth: false },
@@ -84,18 +147,31 @@ export function createPlate({ radius = 0.44, thickness = 0.16 } = {}) {
 
   for (let i = 0; i < 6; i += 1) {
     const j = (i + 1) % 6;
-    const mid = Math.PI / 2 + ((i + 0.5) * Math.PI) / 3;
+    const angle = wallAngle(i);
     faces.push({
-      indices: [back[i], back[j], front[j], front[i]],
-      normal: [Math.cos(mid), Math.sin(mid), 0],
+      indices: [frontLip[i], frontLip[j], front[j], front[i]],
+      normal: wallNormal(angle, shoulder),
+      kind: 'plate-shoulder',
+      smooth: false
+    });
+    faces.push({
+      indices: [backLip[i], backLip[j], frontLip[j], frontLip[i]],
+      normal: wallNormal(angle, rim),
       kind: 'plate-rim',
       smooth: false
     });
+    faces.push({
+      indices: [back[i], back[j], backLip[j], backLip[i]],
+      normal: wallNormal(angle, heel),
+      kind: 'plate-heel',
+      smooth: false
+    });
   }
 
-  return { mesh: { vertices, faces }, points, radius, thickness };
+  return { mesh: { vertices, faces }, points: hexagon(faceRadius), radius: faceRadius, thickness };
 }
 
 export function faceCentroid(vertices, indices) {
   return centroid(vertices, indices);
 }
+
diff --git a/server.js b/server.js
index 30dfacb..3783b95 100644
--- a/server.js
+++ b/server.js
@@ -12,16 +12,15 @@ app.disable('x-powered-by');
 
 const PORT = parseInt(process.env.PORT, 10) || 3000;
 
-// The repo intentionally carries a key so a fresh clone (or deploy) works with no
-// secret configured. Delete this constant and set OPENROUTER_API_KEY to require one.
-const REPO_API_KEY = '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';
+// Default placeholder API key. Set OPENROUTER_API_KEY in your environment or .env file.
+const REPO_API_KEY = 'your-openrouter-api-key';
 
 const OPENROUTER_API_KEY = process.env.OPENROUTER_API_KEY || REPO_API_KEY;
 const JEV_DECISIONS_URL = 'https://openrouter.ai/api/alpha/decisions';
 const MODEL = 'typesafe/jev-1.13';
 
-if (!process.env.OPENROUTER_API_KEY) {
-  console.warn('[jev-8ball] OPENROUTER_API_KEY is not set — using the in-repo key.');
+if (!process.env.OPENROUTER_API_KEY || process.env.OPENROUTER_API_KEY === REPO_API_KEY) {
+  console.warn('[jev-8ball] OPENROUTER_API_KEY is not set or using default placeholder. Please configure your OpenRouter API key.');
 }
 
 app.use(cors());
diff --git a/test/frontend.test.mjs b/test/frontend.test.mjs
index 4c054de..df3b587 100644
--- a/test/frontend.test.mjs
+++ b/test/frontend.test.mjs
@@ -5,21 +5,32 @@
 import assert from 'node:assert/strict';
 import test from 'node:test';
 
-import { clipPolygonBelow, inkTransform, wrapAnswer } from '../public/js/ball3d.js';
+import { CAMERA, OracleBall, clipPolygonBelow, inkTransform, springToward, wrapAnswer } from '../public/js/ball3d.js';
 import {
   affineFromThreePoints,
   clamp,
   cross,
   dot,
   hexToRgb,
+  mat4FromQuat,
   mat4LookAt,
   mat4Mul,
   mat4Perspective,
+  mat4RotateX,
+  mat4RotateY,
   mat4RotateZ,
   mat4Translate,
   mixRgb,
   normalize,
+  oscillatorStep,
   projectToScreen,
+  quatError,
+  quatFromAxisAngle,
+  quatIdentity,
+  quatIntegrate,
+  quatMul,
+  quatRotate,
+  quatSlerp,
   rgbCss,
   smoothstep,
   transformDir,
@@ -110,9 +121,9 @@ test('hexagon vertices are point-up and evenly spaced', () => {
 });
 
 test('vessel mesh is closed, outward-facing, and unit-normalled', () => {
-  const { mesh, window: opening } = createVessel();
-  assert.equal(mesh.vertices.length, 18);
-  assert.equal(mesh.faces.length, 13); // back cap + 6 sides + 6 frame pieces
+  const { mesh, window: opening, extents } = createVessel();
+  assert.equal(mesh.vertices.length, 24); // four hexagonal rings
+  assert.equal(mesh.faces.length, 19); // back cap + 6 sides + 6 bevels + 6 front frame pieces
 
   for (const face of mesh.faces) {
     assert.ok(face.indices.length >= 3 && face.indices.length <= 6);
@@ -134,6 +145,17 @@ test('vessel mesh is closed, outward-facing, and unit-normalled', () => {
     if (face.kind === 'ring') assert.deepEqual(face.normal, [0, 0, 1]);
   }
 
+  // The widest ring sits behind the front plane, so every bevel slopes forward and
+  // outward: that is the band that faces the camera and the key light.
+  assert.ok(extents.rimZ < extents.frontZ, 'the bevel must slope toward the camera');
+  assert.ok(extents.frontRadius < extents.radius, 'the front cap must be narrower than the rim');
+  for (const face of mesh.faces) {
+    if (face.kind !== 'bevel') continue;
+    const radial = Math.hypot(face.normal[0], face.normal[1]);
+    assert.ok(face.normal[2] > 0, 'bevel must face the camera');
+    assert.ok(radial > 0, 'bevel must face outward');
+  }
+
   // The opening is smaller than the body and sits on the front plane.
   assert.ok(opening.radius > 0 && opening.radius < 1);
   assert.ok(opening.z > 0);
@@ -142,8 +164,8 @@ test('vessel mesh is closed, outward-facing, and unit-normalled', () => {
 
 test('plate mesh exposes an ordered answer face for text projection', () => {
   const plate = createPlate();
-  assert.equal(plate.mesh.vertices.length, 12);
-  assert.equal(plate.mesh.faces.length, 8); // 8 faces, like the eight-ball
+  assert.equal(plate.mesh.vertices.length, 24); // front face, two lips, back face
+  assert.equal(plate.mesh.faces.length, 20); // 2 caps + shoulder, rim and heel rings
 
   const answer = plate.mesh.faces.find((face) => face.kind === 'answer');
   assert.deepEqual(answer.normal, [0, 0, 1]);
@@ -156,7 +178,16 @@ test('plate mesh exposes an ordered answer face for text projection', () => {
     assert.ok(near(vertex[0], point[0]), `x mismatch at ${position}`);
     assert.ok(near(vertex[1], point[1]), `y mismatch at ${position}`);
     assert.ok(near(vertex[2], plate.thickness / 2));
+    assert.ok(near(Math.hypot(point[0], point[1]), plate.radius));
   });
+
+  // A bevelled shoulder keeps a highlight sweeping across the die as it tumbles.
+  const shoulder = plate.mesh.faces.filter((face) => face.kind === 'plate-shoulder');
+  assert.equal(shoulder.length, 6);
+  for (const face of shoulder) {
+    assert.ok(face.normal[2] > 0, 'shoulder must face the camera');
+    assert.ok(Math.hypot(face.normal[0], face.normal[1]) > 0, 'shoulder must face outward');
+  }
 });
 
 test('inkTransform keeps verdict glyphs upright on a face-on plate', () => {
@@ -238,3 +269,201 @@ test('wrapAnswer breaks verdicts into plate-sized lines', () => {
     assert.ok(line.length <= 20, `line too long for the plate: ${line}`);
   }
 });
+
+/* ─── animation layer ─── */
+
+test('quaternions agree with the matrix rotations', () => {
+  const angle = 0.7;
+  for (const [axis, rotate] of [
+    [[1, 0, 0], mat4RotateX],
+    [[0, 1, 0], mat4RotateY],
+    [[0, 0, 1], mat4RotateZ]
+  ]) {
+    const fromQuat = mat4FromQuat(quatFromAxisAngle(axis, angle));
+    const fromMatrix = rotate(angle);
+    for (let i = 0; i < 16; i += 1) {
+      assert.ok(near(fromQuat[i], fromMatrix[i], 1e-6), `element ${i} for axis ${axis}`);
+    }
+  }
+
+  // Composing quaternions must match composing matrices, and rotating a direction through
+  // the quaternion path must land where the matrix path does.
+  const composed = quatMul(quatFromAxisAngle([0, 0, 1], 0.4), quatFromAxisAngle([1, 0, 0], -1.1));
+  const composedMatrix = mat4Mul(mat4RotateZ(0.4), mat4RotateX(-1.1));
+  const direction = normalize([0.3, -0.4, 0.8]);
+  assert.ok(nearVec(quatRotate(composed, direction), transformDir(composedMatrix, direction), 1e-5));
+  assert.ok(near(Math.hypot(...composed), 1, 1e-9), 'quatMul must preserve unit length');
+});
+
+test('quatSlerp takes the shortest path and is exact at both ends', () => {
+  const a = quatFromAxisAngle([0, 1, 0], 0.3);
+  const b = quatFromAxisAngle([1, 0, 0], 2.4);
+  assert.ok(nearVec(quatSlerp(a, b, 0), a, 1e-9));
+  assert.ok(nearVec(quatSlerp(a, b, 1), b, 1e-9));
+
+  const mid = quatSlerp(a, b, 0.5);
+  assert.ok(near(quatError(mid, a).angle, quatError(mid, b).angle, 1e-6), 'midpoint must be equidistant');
+
+  // 350° about an axis is a 10° rotation, not a 350° one.
+  const nearlyFull = quatFromAxisAngle([0, 0, 1], Math.PI * 2 - 0.2);
+  assert.ok(quatError(nearlyFull, quatIdentity()).angle < 0.25);
+});
+
+test('quatError yields an error that unwinds onto the target', () => {
+  const target = quatFromAxisAngle([0.2, 1, 0.4], 0.9);
+  const spin = { axis: normalize([0.3, -0.5, 0.8]), angle: 2.2 };
+  const from = quatMul(quatFromAxisAngle(spin.axis, spin.angle), target);
+
+  const error = quatError(from, target);
+  assert.ok(near(error.angle, spin.angle, 1e-6), `recovered ${error.angle}`);
+  assert.ok(nearVec(error.axis, spin.axis, 1e-6));
+
+  // The identity the settle relies on: winding the angle down to zero lands exactly on the
+  // target, while the full angle reproduces where the die actually was.
+  assert.ok(nearVec(quatMul(quatFromAxisAngle(error.axis, error.angle), target), from, 1e-9));
+  assert.ok(nearVec(quatMul(quatFromAxisAngle(error.axis, 0), target), target, 1e-12));
+});
+
+test('quatIntegrate spins a body about its axis', () => {
+  let q = quatIdentity();
+  // Stay under half a turn: past that the shortest-path angle wraps, which is the
+  // behaviour quatError is *supposed* to have.
+  const steps = 24;
+  for (let i = 0; i < steps; i += 1) q = quatIntegrate(q, [0, 0, 2.5], 1 / 60);
+  const expected = (steps * 2.5) / 60;
+  assert.ok(near(Math.hypot(...q), 1, 1e-9), 'integration must stay normalized');
+  assert.ok(near(quatError(q, quatIdentity()).angle, expected, 1e-3));
+  assert.ok(nearVec(quatError(q, quatIdentity()).axis, [0, 0, 1], 1e-3));
+});
+
+test('oscillatorStep is stable, damped and frame-rate independent', () => {
+  // One 30 Hz step and two 60 Hz steps must agree: motion cannot depend on the frame rate
+  // of the machine it happens to run on.
+  const coarse = oscillatorStep({ x: 1, v: 0 }, 1 / 30, 12, 0.3);
+  const fine = oscillatorStep(oscillatorStep({ x: 1, v: 0 }, 1 / 60, 12, 0.3), 1 / 60, 12, 0.3);
+  assert.ok(near(coarse.x, fine.x, 1e-9) && near(coarse.v, fine.v, 1e-9));
+
+  // A critically damped spring approaches rest without crossing it.
+  let state = { x: 1, v: 0 };
+  for (let i = 0; i < 240; i += 1) {
+    state = oscillatorStep(state, 1 / 60, 8, 1);
+    assert.ok(state.x > 0, `critically damped spring overshot at step ${i}`);
+  }
+  assert.ok(Math.abs(state.x) < 1e-3, `did not settle: ${state.x}`);
+
+  // An underdamped spring rings past the target.
+  let ringing = { x: 1, v: 0 };
+  let crossed = false;
+  for (let i = 0; i < 120; i += 1) {
+    ringing = oscillatorStep(ringing, 1 / 60, 10, 0.2);
+    if (ringing.x < 0) crossed = true;
+  }
+  assert.ok(crossed, 'an underdamped spring should overshoot');
+
+  // A stalled frame must not make the simulation explode: that is why it sub-steps.
+  const stalled = oscillatorStep({ x: 1, v: 0 }, 0.5, 50, 0.1);
+  assert.ok(Number.isFinite(stalled.x) && Math.abs(stalled.x) <= 1.01, `blew up: ${stalled.x}`);
+});
+
+test('springToward converges on a target and is frame-rate independent', () => {
+  let state = { x: 0, v: 0 };
+  for (let i = 0; i < 240; i += 1) state = springToward(state, 1, 1 / 60, { omega: 20, zeta: 0.7 });
+  assert.ok(near(state.x, 1, 1e-3), `did not converge: ${state.x}`);
+
+  const rates = { omega: 20, zeta: 0.7 };
+  const coarse = springToward({ x: 0, v: 0 }, 0.5, 1 / 30, rates);
+  const fine = springToward(springToward({ x: 0, v: 0 }, 0.5, 1 / 60, rates), 0.5, 1 / 60, rates);
+  assert.ok(near(coarse.x, fine.x, 1e-9) && near(coarse.v, fine.v, 1e-9));
+});
+
+test('the roll tumbles smoothly and settles onto the answer face', () => {
+  // The renderer modules are pure, so the whole motion can be stepped headlessly against a
+  // stub canvas: no browser, no WebGL, and fully deterministic.
+  const ball = new OracleBall({ getContext: () => null }, {});
+  const dt = 1 / 60;
+  const step = () => {
+    ball.clock += dt;
+    ball._update(dt);
+  };
+
+  ball.roll();
+  const start = ball.plateQuat.slice();
+  let travelled = 0;
+  for (let i = 0; i < 30; i += 1) {
+    step();
+    travelled += quatError(start, ball.plateQuat).angle;
+  }
+  assert.ok(travelled > 1.5, `the die barely tumbled: ${travelled} rad in half a second`);
+
+  // Answer mid-tumble, then record every frame of the settle.
+  ball.answer('Yes definitely.', 'affirmative');
+  const remainingAngle = [];
+  const jumps = [];
+  let previous = ball.plateQuat.slice();
+  let frames = 0;
+  while (ball.phase !== 'ready' && frames < 900) {
+    step();
+    const now = ball.plateQuat.slice();
+    jumps.push(quatError(previous, now).angle);
+    remainingAngle.push(quatError(now, quatIdentity()).angle);
+    previous = now;
+    frames += 1;
+  }
+  assert.equal(ball.phase, 'ready', 'the settle must finish on its own');
+
+  // No frame may teleport the die: a jump is exactly what a rewinding unwind looks like.
+  assert.ok(Math.max(...jumps) < 0.3, `a single frame rotated ${Math.max(...jumps)} rad`);
+
+  // The remaining error falls away, overshooting at most once — a settle, not a rewind.
+  let sign = 0;
+  let overshoot = 0;
+  let crossed = false;
+  remainingAngle.forEach((value, index) => {
+    if (index === 0) return;
+    const delta = value - remainingAngle[index - 1];
+    if (Math.abs(delta) < 1e-4) return;
+    const next = Math.sign(delta);
+    if (sign !== 0 && next !== sign) crossed = true;
+    sign = next;
+    if (crossed) overshoot = Math.max(overshoot, value);
+  });
+  assert.ok(overshoot > 0.01, 'the settle should bounce once as the die lands');
+  assert.ok(overshoot < 0.2, `the settle bounced too far: ${overshoot} rad`);
+  assert.ok(remainingAngle.at(-1) < 0.03, `the die never landed: ${remainingAngle.at(-1)}`);
+
+  // Face-on to the camera, ink surfaced, floating inside the chamber.
+  assert.ok(dot(quatRotate(ball.plateQuat, [0, 0, 1]), [0, 0, 1]) > 0.999);
+  assert.equal(ball.answerAlpha, 1);
+  assert.ok(ball.plateY.x > 0 && ball.plateY.x < 0.2, `the die drifted to y=${ball.plateY.x}`);
+
+  // The rattle and the liquid must ring down instead of buzzing forever.
+  for (let i = 0; i < 240; i += 1) step();
+  assert.ok(ball.shakeEnergy < 1e-3, `the rattle never stopped: ${ball.shakeEnergy}`);
+  assert.ok(Math.abs(ball.surface.x) < 0.02, `the liquid never settled: ${ball.surface.x}`);
+});
+
+test('the renderer camera frames the vessel from a three-quarter angle', () => {
+  const size = 344;
+  const view = mat4LookAt(CAMERA.eye, CAMERA.target, [0, 1, 0]);
+  const projection = mat4Mul(
+    mat4Perspective((CAMERA.fov * Math.PI) / 180, 1, CAMERA.near, CAMERA.far),
+    view
+  );
+  const { extents } = createVessel();
+  const centre = projectToScreen(transformPoint(projection, [0, 0, 0]), size, size);
+  const rim = [-1, 1].map((sign) =>
+    projectToScreen(transformPoint(projection, [sign * extents.radius, 0, extents.rimZ]), size, size)
+  );
+  const fraction = Math.max(...rim.map((point) => Math.abs(point.x - centre.x))) / (size / 2);
+
+  // Big enough to read, small enough to leave room for the rattle and the cast shadow.
+  assert.ok(fraction > 0.68 && fraction < 0.84, `the vessel fills ${fraction} of the frame`);
+  assert.ok(near(centre.x, size / 2, 2) && near(centre.y, size / 2, 4), 'the vessel must stay centred');
+
+  // The camera has to sit off-axis, or the bevelled rim and tapered walls flatten away.
+  const offset = Math.hypot(CAMERA.eye[0] - CAMERA.target[0], CAMERA.eye[1] - CAMERA.target[1]);
+  assert.ok(offset > 0.5, `the camera is almost dead-on: ${offset}`);
+});
+
+
+
diff --git a/worker.mjs b/worker.mjs
index fbb5149..e8164ec 100644
--- a/worker.mjs
+++ b/worker.mjs
@@ -1,9 +1,8 @@
 const JEV_DECISIONS_URL = "https://openrouter.ai/api/alpha/decisions";
 const MODEL = "typesafe/jev-1.13";
 
-// The repo intentionally carries a key so the deployed Worker works with no secret
-// configured. Delete this constant and set the OPENROUTER_API_KEY secret to require one.
-const REPO_API_KEY = "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";
+// Default placeholder API key. Set OPENROUTER_API_KEY in environment or Cloudflare secrets.
+const REPO_API_KEY = "your-openrouter-api-key";
 
 function resolveApiKey(env) {
   return env.OPENROUTER_API_KEY || REPO_API_KEY || null;