diff --git a/html/unity-coordinate-visualizer/.gitignore b/html/unity-coordinate-visualizer/.gitignore
new file mode 100644
index 0000000..a547bf3
--- /dev/null
+++ b/html/unity-coordinate-visualizer/.gitignore
@@ -0,0 +1,24 @@
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
+lerna-debug.log*
+
+node_modules
+dist
+dist-ssr
+*.local
+
+# Editor directories and files
+.vscode/*
+!.vscode/extensions.json
+.idea
+.DS_Store
+*.suo
+*.ntvs*
+*.njsproj
+*.sln
+*.sw?
diff --git a/html/unity-coordinate-visualizer/App.tsx b/html/unity-coordinate-visualizer/App.tsx
new file mode 100644
index 0000000..81dbe7e
--- /dev/null
+++ b/html/unity-coordinate-visualizer/App.tsx
@@ -0,0 +1,379 @@
+import React, { useEffect, useRef, useState, useMemo } from 'react';
+import * as THREE from 'three';
+import { OrbitControls } from 'three/examples/jsm/controls/OrbitControls';
+
+// --- Types & Constants ---
+interface CoordinateState {
+  theta: number; // Yaw
+  phi: number;   // Pitch
+  r: number;     // Radius
+}
+
+const AXIS_LEN = 12;
+
+const App: React.FC = () => {
+  // --- State ---
+  const [coords, setCoords] = useState<CoordinateState>({
+    theta: 45,
+    phi: 30,
+    r: 8
+  });
+
+  // --- Refs for Three.js objects ---
+  const mountRef = useRef<HTMLDivElement>(null);
+  const sceneRef = useRef<{
+    scene: THREE.Scene;
+    camera: THREE.PerspectiveCamera;
+    renderer: THREE.WebGLRenderer;
+    sphereMesh: THREE.Mesh;
+    radiusLine: THREE.Line;
+    projLine: THREE.Line;
+    heightLine: THREE.Line;
+    controls: OrbitControls;
+  } | null>(null);
+
+  // --- Math Logic (Extracted for UI & 3D sync) ---
+  const mathResult = useMemo(() => {
+    const { theta, phi, r } = coords;
+
+    // --- CHANGE HERE: Invert the Phi (Pitch) direction ---
+    // Original was: const radPhi = phi * Math.PI / 180;
+    const radTheta = theta * Math.PI / 180;
+    const radPhi = -phi * Math.PI / 180; // Inverted rotation direction
+
+    const sinT = Math.sin(radTheta);
+    const cosT = Math.cos(radTheta);
+    const sinP = Math.sin(radPhi);
+    const cosP = Math.cos(radPhi);
+
+    // Unity Coordinate Calculation
+    const r_xz = r * cosP; // Projection length on XZ plane
+    const valX = r_xz * sinT;
+    const valY = r * sinP;
+    const valZ = r_xz * cosT;
+
+    return {
+      radTheta,
+      radPhi,
+      sinT, cosT, sinP, cosP,
+      r_xz,
+      valX, valY, valZ
+    };
+  }, [coords]);
+
+  // --- Initialize Three.js Scene ---
+  useEffect(() => {
+    if (!mountRef.current) return;
+
+    // 1. Scene Setup
+    const scene = new THREE.Scene();
+    scene.background = new THREE.Color(0x1a1a1a);
+
+    const width = mountRef.current.clientWidth;
+    const height = mountRef.current.clientHeight;
+    const camera = new THREE.PerspectiveCamera(45, width / height, 0.1, 1000);
+    camera.position.set(0, 5, 20);
+
+    const renderer = new THREE.WebGLRenderer({ antialias: true });
+    renderer.setSize(width, height);
+    renderer.setPixelRatio(window.devicePixelRatio);
+    mountRef.current.appendChild(renderer.domElement);
+
+    const controls = new OrbitControls(camera, renderer.domElement);
+    controls.enableDamping = true;
+
+    // 2. Helpers
+    const gridHelper = new THREE.GridHelper(30, 30, 0x444444, 0x222222);
+    scene.add(gridHelper);
+
+    // 3. Axes Creation Helper
+    const createLine = (start: THREE.Vector3, end: THREE.Vector3, color: number, dashed = false) => {
+      const points = [start, end];
+      const geo = new THREE.BufferGeometry().setFromPoints(points);
+      let mat: THREE.Material;
+      if (dashed) {
+        mat = new THREE.LineDashedMaterial({ color, dashSize: 0.5, gapSize: 0.3, scale: 1 });
+      } else {
+        mat = new THREE.LineBasicMaterial({ color, linewidth: 2 });
+      }
+      const line = new THREE.Line(geo, mat);
+      if (dashed) line.computeLineDistances();
+      return line;
+    };
+
+    // Axes
+    scene.add(createLine(new THREE.Vector3(0, 0, 0), new THREE.Vector3(AXIS_LEN, 0, 0), 0xff0000)); // X
+    scene.add(createLine(new THREE.Vector3(0, 0, 0), new THREE.Vector3(0, AXIS_LEN, 0), 0x00ff00)); // Y
+    scene.add(createLine(new THREE.Vector3(0, 0, 0), new THREE.Vector3(0, 0, -AXIS_LEN), 0x0066ff)); // Z (Visualized into screen)
+
+    // Labels (Using Sprites)
+    const addLabel = (text: string, pos: THREE.Vector3, colorStr: string) => {
+      const canvas = document.createElement('canvas');
+      const ctx = canvas.getContext('2d');
+      if (ctx) {
+        canvas.width = 64; canvas.height = 64;
+        ctx.fillStyle = colorStr;
+        ctx.font = "bold 48px Arial";
+        ctx.textAlign = "center";
+        ctx.textBaseline = "middle";
+        ctx.fillText(text, 32, 32);
+        const texture = new THREE.CanvasTexture(canvas);
+        const spriteMat = new THREE.SpriteMaterial({ map: texture });
+        const sprite = new THREE.Sprite(spriteMat);
+        sprite.position.copy(pos);
+        sprite.scale.set(1.5, 1.5, 1.5);
+        scene.add(sprite);
+      }
+    };
+
+    addLabel("X", new THREE.Vector3(AXIS_LEN + 1, 0, 0), "#ff5555");
+    addLabel("Y", new THREE.Vector3(0, AXIS_LEN + 1, 0), "#55ff55");
+    addLabel("Z", new THREE.Vector3(0, 0, -AXIS_LEN - 1), "#5588ff");
+
+    // 4. Dynamic Objects
+    const sphereMesh = new THREE.Mesh(
+      new THREE.SphereGeometry(0.4, 32, 32),
+      new THREE.MeshBasicMaterial({ color: 0xffff00 })
+    );
+    scene.add(sphereMesh);
+
+    const radiusLine = createLine(new THREE.Vector3(), new THREE.Vector3(), 0xffff00, true);
+    const projLine = createLine(new THREE.Vector3(), new THREE.Vector3(), 0x00aa00);
+    const heightLine = createLine(new THREE.Vector3(), new THREE.Vector3(), 0x00aaff);
+    scene.add(radiusLine, projLine, heightLine);
+
+    // Store refs
+    sceneRef.current = {
+      scene, camera, renderer, sphereMesh, radiusLine, projLine, heightLine, controls
+    };
+
+    // Animation Loop
+    const animate = () => {
+      requestAnimationFrame(animate);
+      controls.update();
+      renderer.render(scene, camera);
+    };
+    animate();
+
+    // Cleanup
+    return () => {
+      if (mountRef.current) {
+        mountRef.current.removeChild(renderer.domElement);
+      }
+      renderer.dispose();
+    };
+  }, []);
+
+  // --- Update Scene when Coordinates Change ---
+  useEffect(() => {
+    if (!sceneRef.current) return;
+
+    const { sphereMesh, radiusLine, projLine, heightLine } = sceneRef.current;
+    const { valX, valY, valZ } = mathResult;
+
+    // Unity Z+ is "Forward". In Three.js (WebGL), "Forward" into the screen is Z-.
+    // To visually match the Unity inspector logic where Z+ goes "into" the scene relative to camera start:
+    const renderX = valX;
+    const renderY = valY;
+    const renderZ = -valZ; 
+
+    sphereMesh.position.set(renderX, renderY, renderZ);
+
+    const origin = new THREE.Vector3(0, 0, 0);
+    const target = new THREE.Vector3(renderX, renderY, renderZ);
+    const ground = new THREE.Vector3(renderX, 0, renderZ);
+
+    // Update lines
+    radiusLine.geometry.setFromPoints([origin, target]);
+    radiusLine.computeLineDistances(); // Necessary for dashed lines
+    radiusLine.geometry.attributes.position.needsUpdate = true;
+
+    projLine.geometry.setFromPoints([origin, ground]);
+    projLine.geometry.attributes.position.needsUpdate = true;
+
+    heightLine.geometry.setFromPoints([ground, target]);
+    heightLine.geometry.attributes.position.needsUpdate = true;
+
+  }, [mathResult]);
+
+  // --- Resize Handler ---
+  useEffect(() => {
+    const handleResize = () => {
+      if (!mountRef.current || !sceneRef.current) return;
+      const width = window.innerWidth;
+      const height = window.innerHeight;
+      const { camera, renderer } = sceneRef.current;
+      
+      camera.aspect = width / height;
+      camera.updateProjectionMatrix();
+      renderer.setSize(width, height);
+    };
+    window.addEventListener('resize', handleResize);
+    return () => window.removeEventListener('resize', handleResize);
+  }, []);
+
+  // --- UI Handlers ---
+  const handleChange = (key: keyof CoordinateState, value: number) => {
+    setCoords(prev => ({ ...prev, [key]: value }));
+  };
+
+  return (
+    <div className="relative w-full h-screen bg-neutral-900">
+      {/* 3D Canvas Container */}
+      <div ref={mountRef} className="w-full h-full cursor-move" />
+
+      {/* UI Overlay */}
+      <div className="absolute top-4 left-4 w-[400px] max-h-[90vh] overflow-y-auto custom-scrollbar bg-neutral-800/95 backdrop-blur-sm border border-neutral-700 rounded-lg shadow-2xl p-5 flex flex-col gap-4">
+        
+        <div className="border-b border-neutral-600 pb-3">
+          <h3 className="text-xl font-semibold text-sky-400">Unity Coordinates</h3>
+          <p className="text-xs text-neutral-400 mt-1">
+            System: X-Right, Y-Up, <span className="text-blue-400 font-bold">Z-Forward (Into Screen)</span>
+          </p>
+          <p className="text-xs text-amber-400 mt-1 font-mono">
+            * Pitch direction inverted
+          </p>
+        </div>
+
+        {/* Controls */}
+        <div className="space-y-4">
+          <ControlRow 
+            label="Theta (Yaw) [-180 ~ 180]"
+            value={coords.theta}
+            min={-180} max={180} step={1}
+            onChange={(v) => handleChange('theta', v)}
+          />
+          <ControlRow 
+            label="Phi (Pitch) [-90 ~ 90]"
+            value={coords.phi}
+            min={-90} max={90} step={1}
+            onChange={(v) => handleChange('phi', v)}
+          />
+          <ControlRow 
+            label="Radius (r) [1 ~ 15]"
+            value={coords.r}
+            min={1} max={15} step={0.1}
+            onChange={(v) => handleChange('r', v)}
+          />
+        </div>
+
+        {/* Calculations Display */}
+        <div className="mt-2">
+          <h4 className="text-sm font-semibold text-amber-400 border-l-4 border-amber-400 pl-2 mb-2">Calculation Logic</h4>
+          
+          <div className="bg-black/40 p-3 rounded border border-neutral-700 font-mono text-xs leading-relaxed text-neutral-300">
+            {/* Step 1 */}
+            <div className="mb-3 border-b border-dashed border-neutral-700 pb-2">
+              <div className="text-green-400 italic mb-1">// 1. Deg to Rad (Pitch Inverted)</div>
+              <div>&theta; = {coords.theta}&deg; &rArr; sin: {mathResult.sinT.toFixed(3)}, cos: {mathResult.cosT.toFixed(3)}</div>
+              <div>&phi; = <span className='text-red-400'>-({coords.phi})</span>&deg; &rArr; sin: {mathResult.sinP.toFixed(3)}, cos: {mathResult.cosP.toFixed(3)}</div>
+            </div>
+
+            {/* Step 2 */}
+            <div className="mb-3 border-b border-dashed border-neutral-700 pb-2">
+              <div className="text-green-400 italic mb-1">// 2. XZ Plane Projection</div>
+              <div>
+                <span className="text-sky-300 font-bold">r_xz</span> = r * cos(&phi;)
+              </div>
+              <div className="pl-4 text-neutral-400">
+                = {coords.r} * {mathResult.cosP.toFixed(3)} = <span className="text-sky-200 font-bold">{mathResult.r_xz.toFixed(3)}</span>
+              </div>
+            </div>
+
+            {/* Step 3 */}
+            <div>
+              <div className="text-green-400 italic mb-1">// 3. Unity Vectors</div>
+              
+              {/* Y */}
+              <div className="flex justify-between">
+                <span><span className="text-green-400 font-bold">Y (Up)</span> = r * sin(&phi;)</span>
+              </div>
+              <div className="pl-4 text-neutral-400 mb-1">
+                 = {coords.r} * {mathResult.sinP.toFixed(3)} = <span className="text-green-300 font-bold">{mathResult.valY.toFixed(2)}</span>
+              </div>
+
+              {/* X */}
+              <div className="flex justify-between">
+                <span><span className="text-red-400 font-bold">X (Right)</span> = r_xz * sin(&theta;)</span>
+              </div>
+              <div className="pl-4 text-neutral-400 mb-1">
+                = {mathResult.r_xz.toFixed(3)} * {mathResult.sinT.toFixed(3)} = <span className="text-red-300 font-bold">{mathResult.valX.toFixed(2)}</span>
+              </div>
+
+              {/* Z */}
+              <div className="flex justify-between">
+                <span><span className="text-blue-400 font-bold">Z (Fwd)</span> = r_xz * cos(&theta;)</span>
+              </div>
+              <div className="pl-4 text-neutral-400">
+                = {mathResult.r_xz.toFixed(3)} * {mathResult.cosT.toFixed(3)} = <span className="text-blue-300 font-bold">{mathResult.valZ.toFixed(2)}</span>
+              </div>
+            </div>
+          </div>
+        </div>
+
+        {/* Result Grid */}
+        <div className="grid grid-cols-3 gap-2 font-mono text-sm font-bold text-center shadow-inner">
+          <div className="bg-red-900/40 border border-red-500/50 text-red-200 p-2 rounded">
+            X: {mathResult.valX.toFixed(2)}
+          </div>
+          <div className="bg-green-900/40 border border-green-500/50 text-green-200 p-2 rounded">
+            Y: {mathResult.valY.toFixed(2)}
+          </div>
+          <div className="bg-blue-900/40 border border-blue-500/50 text-blue-200 p-2 rounded">
+            Z: {mathResult.valZ.toFixed(2)}
+          </div>
+        </div>
+
+      </div>
+
+      {/* Footer Tooltip */}
+      <div className="absolute bottom-6 w-full text-center pointer-events-none select-none">
+        <span className="text-neutral-500 text-sm drop-shadow-md bg-black/50 px-3 py-1 rounded-full">
+          Left Click: Rotate · Right Click: Pan · Scroll: Zoom
+        </span>
+      </div>
+    </div>
+  );
+};
+
+// --- Sub-component for Slider+Input ---
+interface ControlRowProps {
+  label: string;
+  value: number;
+  min: number;
+  max: number;
+  step: number;
+  onChange: (val: number) => void;
+}
+
+const ControlRow: React.FC<ControlRowProps> = ({ label, value, min, max, step, onChange }) => {
+  return (
+    <div className="flex flex-col gap-1">
+      <label className="text-xs text-neutral-400">{label}</label>
+      <div className="flex items-center gap-3">
+        <input
+          type="range"
+          min={min} max={max} step={step}
+          value={value}
+          onChange={(e) => onChange(parseFloat(e.target.value))}
+          className="flex-grow h-1 bg-neutral-600 rounded-lg appearance-none cursor-pointer accent-sky-500 hover:accent-sky-400 transition-all"
+        />
+        <input
+          type="number"
+          min={min} max={max} step={step}
+          value={value}
+          onChange={(e) => {
+            let v = parseFloat(e.target.value);
+            if (isNaN(v)) return;
+            if (v < min) v = min;
+            if (v > max) v = max;
+            onChange(v);
+          }}
+          className="w-16 bg-neutral-950 border border-neutral-600 text-white text-right text-sm p-1 rounded focus:outline-none focus:border-sky-500 font-mono"
+        />
+      </div>
+    </div>
+  );
+};
+
+export default App;
diff --git a/html/unity-coordinate-visualizer/README.md b/html/unity-coordinate-visualizer/README.md
new file mode 100644
index 0000000..c83afef
--- /dev/null
+++ b/html/unity-coordinate-visualizer/README.md
@@ -0,0 +1,20 @@
+<div align="center">
+<img width="1200" height="475" alt="GHBanner" src="https://github.com/user-attachments/assets/0aa67016-6eaf-458a-adb2-6e31a0763ed6" />
+</div>
+
+# Run and deploy your AI Studio app
+
+This contains everything you need to run your app locally.
+
+View your app in AI Studio: https://ai.studio/apps/drive/1xK1SY-nHdgcy_n6gMkYNyMPdNrp-RAif
+
+## Run Locally
+
+**Prerequisites:**  Node.js
+
+
+1. Install dependencies:
+   `npm install`
+2. Set the `GEMINI_API_KEY` in [.env.local](.env.local) to your Gemini API key
+3. Run the app:
+   `npm run dev`
diff --git a/html/unity-coordinate-visualizer/index.html b/html/unity-coordinate-visualizer/index.html
new file mode 100644
index 0000000..370cd95
--- /dev/null
+++ b/html/unity-coordinate-visualizer/index.html
@@ -0,0 +1,41 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1" />
+    <title>Unity Coordinate Visualizer</title>
+    <script src="https://cdn.tailwindcss.com"></script>
+    <style>
+      /* Custom scrollbar for the overlay */
+      .custom-scrollbar::-webkit-scrollbar {
+        width: 6px;
+      }
+      .custom-scrollbar::-webkit-scrollbar-track {
+        background: #2d2d2d;
+      }
+      .custom-scrollbar::-webkit-scrollbar-thumb {
+        background: #555;
+        border-radius: 3px;
+      }
+      .custom-scrollbar::-webkit-scrollbar-thumb:hover {
+        background: #777;
+      }
+    </style>
+  <script type="importmap">
+{
+  "imports": {
+    "react/": "https://aistudiocdn.com/react@^19.2.0/",
+    "react": "https://aistudiocdn.com/react@^19.2.0",
+    "three/": "https://aistudiocdn.com/three@^0.181.2/",
+    "three": "https://aistudiocdn.com/three@^0.181.2",
+    "react-dom/": "https://aistudiocdn.com/react-dom@^19.2.0/"
+  }
+}
+</script>
+<link rel="stylesheet" href="/index.css">
+</head>
+  <body class="bg-neutral-900 text-white overflow-hidden">
+    <div id="root"></div>
+  <script type="module" src="/index.tsx"></script>
+</body>
+</html>
\ No newline at end of file
diff --git a/html/unity-coordinate-visualizer/index.tsx b/html/unity-coordinate-visualizer/index.tsx
new file mode 100644
index 0000000..6ca5361
--- /dev/null
+++ b/html/unity-coordinate-visualizer/index.tsx
@@ -0,0 +1,15 @@
+import React from 'react';
+import ReactDOM from 'react-dom/client';
+import App from './App';
+
+const rootElement = document.getElementById('root');
+if (!rootElement) {
+  throw new Error("Could not find root element to mount to");
+}
+
+const root = ReactDOM.createRoot(rootElement);
+root.render(
+  <React.StrictMode>
+    <App />
+  </React.StrictMode>
+);
\ No newline at end of file
diff --git a/html/unity-coordinate-visualizer/metadata.json b/html/unity-coordinate-visualizer/metadata.json
new file mode 100644
index 0000000..f52b9c9
--- /dev/null
+++ b/html/unity-coordinate-visualizer/metadata.json
@@ -0,0 +1,5 @@
+{
+  "name": "Unity Coordinate Visualizer",
+  "description": "A 3D interactive visualization of Unity coordinate system (Left-handed, Z-forward) demonstrating the relationship between spherical inputs (Yaw/Pitch/Radius) and Cartesian coordinates.",
+  "requestFramePermissions": []
+}
\ No newline at end of file
diff --git a/html/unity-coordinate-visualizer/package.json b/html/unity-coordinate-visualizer/package.json
new file mode 100644
index 0000000..03a5d78
--- /dev/null
+++ b/html/unity-coordinate-visualizer/package.json
@@ -0,0 +1,22 @@
+{
+  "name": "unity-coordinate-visualizer",
+  "private": true,
+  "version": "0.0.0",
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "vite build",
+    "preview": "vite preview"
+  },
+  "dependencies": {
+    "react": "^19.2.0",
+    "three": "^0.181.2",
+    "react-dom": "^19.2.0"
+  },
+  "devDependencies": {
+    "@types/node": "^22.14.0",
+    "@vitejs/plugin-react": "^5.0.0",
+    "typescript": "~5.8.2",
+    "vite": "^6.2.0"
+  }
+}
diff --git a/html/unity-coordinate-visualizer/tsconfig.json b/html/unity-coordinate-visualizer/tsconfig.json
new file mode 100644
index 0000000..2c6eed5
--- /dev/null
+++ b/html/unity-coordinate-visualizer/tsconfig.json
@@ -0,0 +1,29 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "experimentalDecorators": true,
+    "useDefineForClassFields": false,
+    "module": "ESNext",
+    "lib": [
+      "ES2022",
+      "DOM",
+      "DOM.Iterable"
+    ],
+    "skipLibCheck": true,
+    "types": [
+      "node"
+    ],
+    "moduleResolution": "bundler",
+    "isolatedModules": true,
+    "moduleDetection": "force",
+    "allowJs": true,
+    "jsx": "react-jsx",
+    "paths": {
+      "@/*": [
+        "./*"
+      ]
+    },
+    "allowImportingTsExtensions": true,
+    "noEmit": true
+  }
+}
\ No newline at end of file
diff --git a/html/unity-coordinate-visualizer/vite.config.ts b/html/unity-coordinate-visualizer/vite.config.ts
new file mode 100644
index 0000000..ee5fb8d
--- /dev/null
+++ b/html/unity-coordinate-visualizer/vite.config.ts
@@ -0,0 +1,23 @@
+import path from 'path';
+import { defineConfig, loadEnv } from 'vite';
+import react from '@vitejs/plugin-react';
+
+export default defineConfig(({ mode }) => {
+    const env = loadEnv(mode, '.', '');
+    return {
+      server: {
+        port: 3000,
+        host: '0.0.0.0',
+      },
+      plugins: [react()],
+      define: {
+        'process.env.API_KEY': JSON.stringify(env.GEMINI_API_KEY),
+        'process.env.GEMINI_API_KEY': JSON.stringify(env.GEMINI_API_KEY)
+      },
+      resolve: {
+        alias: {
+          '@': path.resolve(__dirname, '.'),
+        }
+      }
+    };
+});