diff --git a/TODO.md b/TODO.md
index 788658364..36f72a50a 100644
--- a/TODO.md
+++ b/TODO.md
@@ -28,12 +28,12 @@ A step-by-step checklist for porting MatterControl's design features to a Vue +
 ## Phase 2: 3D Viewport Foundation
 
 ### three.js Setup
-- [ ] Install three.js and `@types/three`
-- [ ] Create `Viewport.vue` component with canvas element
-- [ ] Initialize three.js Scene, Camera, and Renderer
-- [ ] Add resize observer for responsive canvas
-- [ ] Implement render loop with `requestAnimationFrame`
-- [ ] Add basic lighting (ambient + two directional)
+- [x] Install three.js and `@types/three`
+- [x] Create `Viewport.vue` component with canvas element
+- [x] Initialize three.js Scene, Camera, and Renderer
+- [x] Add resize observer for responsive canvas
+- [x] Implement render loop with `requestAnimationFrame`
+- [x] Add basic lighting (ambient + two directional)
 
 ### Scene Helpers
 - [ ] Add ground grid helper (XZ plane)
diff --git a/package.json b/package.json
index 6ec062bd4..ff5a98df9 100644
--- a/package.json
+++ b/package.json
@@ -14,11 +14,13 @@
   },
   "dependencies": {
     "pinia": "^3.0.4",
+    "three": "^0.182.0",
     "vue": "^3.5.24"
   },
   "devDependencies": {
     "@eslint/js": "^9.39.2",
     "@types/node": "^24.10.1",
+    "@types/three": "^0.182.0",
     "@vitejs/plugin-vue": "^6.0.1",
     "@vue/test-utils": "^2.4.6",
     "@vue/tsconfig": "^0.8.1",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 18ccbe4df..352e58c31 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -11,6 +11,9 @@ importers:
       pinia:
         specifier: ^3.0.4
         version: 3.0.4(typescript@5.9.3)(vue@3.5.27(typescript@5.9.3))
+      three:
+        specifier: ^0.182.0
+        version: 0.182.0
       vue:
         specifier: ^3.5.24
         version: 3.5.27(typescript@5.9.3)
@@ -21,6 +24,9 @@ importers:
       '@types/node':
         specifier: ^24.10.1
         version: 24.10.9
+      '@types/three':
+        specifier: ^0.182.0
+        version: 0.182.0
       '@vitejs/plugin-vue':
         specifier: ^6.0.1
         version: 6.0.3(vite@7.3.1(@types/node@24.10.9))(vue@3.5.27(typescript@5.9.3))
@@ -80,6 +86,9 @@ packages:
     resolution: {integrity: sha512-0ZrskXVEHSWIqZM/sQZ4EV3jZJXRkio/WCxaqKZP1g//CEWEPSfeZFcms4XeKBCHU0ZKnIkdJeU/kF+eRp5lBg==}
     engines: {node: '>=6.9.0'}
 
+  '@dimforge/rapier3d-compat@0.12.0':
+    resolution: {integrity: sha512-uekIGetywIgopfD97oDL5PfeezkFpNhwlzlaEYNOA0N6ghdsOvh/HYjSMek5Q2O1PYvRSDFcqFVJl4r4ZBwOow==}
+
   '@esbuild/aix-ppc64@0.27.2':
     resolution: {integrity: sha512-GZMB+a0mOMZs4MpDbj8RJp4cw+w1WV5NYD6xzgvzUJ5Ek2jerwfO2eADyI6ExDSUED+1X8aMbegahsJi+8mgpw==}
     engines: {node: '>=18'}
@@ -435,6 +444,9 @@ packages:
   '@standard-schema/spec@1.1.0':
     resolution: {integrity: sha512-l2aFy5jALhniG5HgqrD6jXLi/rUWrKvqN/qJx6yoJsgKhblVd+iqqU4RCXavm/jPityDo5TCvKMnpjKnOriy0w==}
 
+  '@tweenjs/tween.js@23.1.3':
+    resolution: {integrity: sha512-vJmvvwFxYuGnF2axRtPYocag6Clbb5YS7kLL+SO/TeVFzHqDIWrNKYtcsPMibjDx9O+bu+psAy9NKfWklassUA==}
+
   '@types/chai@5.2.3':
     resolution: {integrity: sha512-Mw558oeA9fFbv65/y4mHtXDs9bPnFMZAL/jxdPFUpOHHIXX91mcgEHbS5Lahr+pwZFR8A7GQleRWeI6cGFC2UA==}
 
@@ -450,6 +462,15 @@ packages:
   '@types/node@24.10.9':
     resolution: {integrity: sha512-ne4A0IpG3+2ETuREInjPNhUGis1SFjv1d5asp8MzEAGtOZeTeHVDOYqOgqfhvseqg/iXty2hjBf1zAOb7RNiNw==}
 
+  '@types/stats.js@0.17.4':
+    resolution: {integrity: sha512-jIBvWWShCvlBqBNIZt0KAshWpvSjhkwkEu4ZUcASoAvhmrgAUI2t1dXrjSL4xXVLB4FznPrIsX3nKXFl/Dt4vA==}
+
+  '@types/three@0.182.0':
+    resolution: {integrity: sha512-WByN9V3Sbwbe2OkWuSGyoqQO8Du6yhYaXtXLoA5FkKTUJorZ+yOHBZ35zUUPQXlAKABZmbYp5oAqpA4RBjtJ/Q==}
+
+  '@types/webxr@0.5.24':
+    resolution: {integrity: sha512-h8fgEd/DpoS9CBrjEQXR+dIDraopAEfu4wYVNY2tEPwk60stPWhvZMf4Foo5FakuQ7HFZoa8WceaWFervK2Ovg==}
+
   '@types/whatwg-mimetype@3.0.2':
     resolution: {integrity: sha512-c2AKvDT8ToxLIOUlN51gTiHXflsfIFisS4pO7pDPoKouJCESkhZnEy623gwP9laCy5lnLDAw1vAzu2vM2YLOrA==}
 
@@ -615,6 +636,9 @@ packages:
       vue:
         optional: true
 
+  '@webgpu/types@0.1.69':
+    resolution: {integrity: sha512-RPmm6kgRbI8e98zSD3RVACvnuktIja5+yLgDAkTmxLr90BEwdTXRQWNLF3ETTTyH/8mKhznZuN5AveXYFEsMGQ==}
+
   abbrev@2.0.0:
     resolution: {integrity: sha512-6/mh1E2u2YgEsCHdY0Yx5oW+61gZU+1vXaoiHHrpKeuRNNgFvS+/jrwHiQhB5apAf5oB7UB7E19ol2R2LKH8hQ==}
     engines: {node: ^14.17.0 || ^16.13.0 || >=18.0.0}
@@ -854,6 +878,9 @@ packages:
       picomatch:
         optional: true
 
+  fflate@0.8.2:
+    resolution: {integrity: sha512-cPJU47OaAoCbg0pBvzsgpTPhmhqI5eJjh/JIu8tPj5q+T7iLvW/JAYUqmE7KOB4R1ZyEhzBaIQpQpardBF5z8A==}
+
   file-entry-cache@8.0.0:
     resolution: {integrity: sha512-XXTUwCvisa5oacNGRP9SfNtYBNAMi+RPwBFmblZEF7N7swHYQS6/Zfk7SRwx4D5j3CH211YNRco1DEMNVfZCnQ==}
     engines: {node: '>=16.0.0'}
@@ -984,6 +1011,9 @@ packages:
   magic-string@0.30.21:
     resolution: {integrity: sha512-vd2F4YUyEXKGcLHoq+TEyCjxueSeHnFxyyjNp80yg0XV4vUhnDer/lvvlqM/arB5bXQN5K2/3oinyCRyx8T2CQ==}
 
+  meshoptimizer@0.22.0:
+    resolution: {integrity: sha512-IebiK79sqIy+E4EgOr+CAw+Ke8hAspXKzBd0JdgEmPHiAwmvEj2S4h1rfvo+o/BnfEYd/jAOg5IeeIjzlzSnDg==}
+
   minimatch@3.1.2:
     resolution: {integrity: sha512-J7p63hRiAjw1NDEww1W7i37+ByIrOWO5XQQAzZ3VOcL0PNybwpfmV/N05zFAzwQ9USyEcX6t3UO+K5aqBQOIHw==}
 
@@ -1181,6 +1211,9 @@ packages:
     resolution: {integrity: sha512-qpCAvRl9stuOHveKsn7HncJRvv501qIacKzQlO/+Lwxc9+0q2wLyv4Dfvt80/DPn2pqOBsJdDiogXGR9+OvwRw==}
     engines: {node: '>=8'}
 
+  three@0.182.0:
+    resolution: {integrity: sha512-GbHabT+Irv+ihI1/f5kIIsZ+Ef9Sl5A1Y7imvS5RQjWgtTPfPnZ43JmlYI7NtCRDK9zir20lQpfg8/9Yd02OvQ==}
+
   tinybench@2.9.0:
     resolution: {integrity: sha512-0+DUvqWMValLmha6lr4kD8iAMK1HzV0/aKnCtWb9v9641TnP/MFb7Pc2bxoxQjTXAErryXVgUOfv2YqNllqGeg==}
 
@@ -1388,6 +1421,8 @@ snapshots:
       '@babel/helper-string-parser': 7.27.1
       '@babel/helper-validator-identifier': 7.28.5
 
+  '@dimforge/rapier3d-compat@0.12.0': {}
+
   '@esbuild/aix-ppc64@0.27.2':
     optional: true
 
@@ -1618,6 +1653,8 @@ snapshots:
 
   '@standard-schema/spec@1.1.0': {}
 
+  '@tweenjs/tween.js@23.1.3': {}
+
   '@types/chai@5.2.3':
     dependencies:
       '@types/deep-eql': 4.0.2
@@ -1633,6 +1670,20 @@ snapshots:
     dependencies:
       undici-types: 7.16.0
 
+  '@types/stats.js@0.17.4': {}
+
+  '@types/three@0.182.0':
+    dependencies:
+      '@dimforge/rapier3d-compat': 0.12.0
+      '@tweenjs/tween.js': 23.1.3
+      '@types/stats.js': 0.17.4
+      '@types/webxr': 0.5.24
+      '@webgpu/types': 0.1.69
+      fflate: 0.8.2
+      meshoptimizer: 0.22.0
+
+  '@types/webxr@0.5.24': {}
+
   '@types/whatwg-mimetype@3.0.2': {}
 
   '@types/ws@8.18.1':
@@ -1879,6 +1930,8 @@ snapshots:
       typescript: 5.9.3
       vue: 3.5.27(typescript@5.9.3)
 
+  '@webgpu/types@0.1.69': {}
+
   abbrev@2.0.0: {}
 
   acorn-jsx@5.3.2(acorn@8.15.0):
@@ -2120,6 +2173,8 @@ snapshots:
     optionalDependencies:
       picomatch: 4.0.3
 
+  fflate@0.8.2: {}
+
   file-entry-cache@8.0.0:
     dependencies:
       flat-cache: 4.0.1
@@ -2247,6 +2302,8 @@ snapshots:
     dependencies:
       '@jridgewell/sourcemap-codec': 1.5.5
 
+  meshoptimizer@0.22.0: {}
+
   minimatch@3.1.2:
     dependencies:
       brace-expansion: 1.1.12
@@ -2434,6 +2491,8 @@ snapshots:
     dependencies:
       has-flag: 4.0.0
 
+  three@0.182.0: {}
+
   tinybench@2.9.0: {}
 
   tinyexec@1.0.2: {}
diff --git a/src/App.vue b/src/App.vue
index 58b0f21b1..3b51102f8 100644
--- a/src/App.vue
+++ b/src/App.vue
@@ -1,30 +1,16 @@
 <script setup lang="ts">
-import HelloWorld from './components/HelloWorld.vue'
+import Viewport from './components/Viewport.vue'
 </script>
 
 <template>
-  <div>
-    <a href="https://vite.dev" target="_blank">
-      <img src="/vite.svg" class="logo" alt="Vite logo" />
-    </a>
-    <a href="https://vuejs.org/" target="_blank">
-      <img src="./assets/vue.svg" class="logo vue" alt="Vue logo" />
-    </a>
+  <div class="app">
+    <Viewport />
   </div>
-  <HelloWorld msg="Vite + Vue" />
 </template>
 
 <style scoped>
-.logo {
-  height: 6em;
-  padding: 1.5em;
-  will-change: filter;
-  transition: filter 300ms;
-}
-.logo:hover {
-  filter: drop-shadow(0 0 2em #646cffaa);
-}
-.logo.vue:hover {
-  filter: drop-shadow(0 0 2em #42b883aa);
+.app {
+  width: 100vw;
+  height: 100vh;
 }
 </style>
diff --git a/src/components/Viewport.vue b/src/components/Viewport.vue
new file mode 100644
index 000000000..a82f01c5e
--- /dev/null
+++ b/src/components/Viewport.vue
@@ -0,0 +1,124 @@
+<script setup lang="ts">
+import { ref, onMounted, onBeforeUnmount } from 'vue'
+import * as THREE from 'three'
+
+const containerRef = ref<HTMLDivElement | null>(null)
+
+let scene: THREE.Scene
+let camera: THREE.PerspectiveCamera
+let renderer: THREE.WebGLRenderer
+let animationFrameId: number
+let resizeObserver: ResizeObserver
+
+function initScene() {
+  if (!containerRef.value) return
+
+  // Create scene
+  scene = new THREE.Scene()
+  scene.background = new THREE.Color(0x1a1a2e)
+
+  // Create camera
+  const { clientWidth: width, clientHeight: height } = containerRef.value
+  camera = new THREE.PerspectiveCamera(45, width / height, 0.1, 1000)
+  camera.position.set(5, 5, 5)
+  camera.lookAt(0, 0, 0)
+
+  // Create renderer
+  renderer = new THREE.WebGLRenderer({ antialias: true })
+  renderer.setSize(width, height)
+  renderer.setPixelRatio(window.devicePixelRatio)
+  containerRef.value.appendChild(renderer.domElement)
+
+  // Add lighting
+  addLighting()
+
+  // Add a test cube to verify rendering
+  addTestCube()
+
+  // Setup resize observer
+  setupResizeObserver()
+
+  // Start render loop
+  animate()
+}
+
+function addLighting() {
+  // Ambient light for base illumination
+  const ambientLight = new THREE.AmbientLight(0xffffff, 0.4)
+  scene.add(ambientLight)
+
+  // Primary directional light (top-front-right)
+  const directionalLight1 = new THREE.DirectionalLight(0xffffff, 0.8)
+  directionalLight1.position.set(5, 10, 7)
+  scene.add(directionalLight1)
+
+  // Secondary directional light (back-left, softer)
+  const directionalLight2 = new THREE.DirectionalLight(0xffffff, 0.3)
+  directionalLight2.position.set(-5, 5, -5)
+  scene.add(directionalLight2)
+}
+
+function addTestCube() {
+  const geometry = new THREE.BoxGeometry(1, 1, 1)
+  const material = new THREE.MeshStandardMaterial({ color: 0x4a90d9 })
+  const cube = new THREE.Mesh(geometry, material)
+  scene.add(cube)
+}
+
+function setupResizeObserver() {
+  if (!containerRef.value) return
+
+  resizeObserver = new ResizeObserver((entries) => {
+    for (const entry of entries) {
+      const { width, height } = entry.contentRect
+      if (width > 0 && height > 0) {
+        camera.aspect = width / height
+        camera.updateProjectionMatrix()
+        renderer.setSize(width, height)
+      }
+    }
+  })
+
+  resizeObserver.observe(containerRef.value)
+}
+
+function animate() {
+  animationFrameId = requestAnimationFrame(animate)
+  renderer.render(scene, camera)
+}
+
+function cleanup() {
+  if (animationFrameId) {
+    cancelAnimationFrame(animationFrameId)
+  }
+
+  if (resizeObserver) {
+    resizeObserver.disconnect()
+  }
+
+  if (renderer) {
+    renderer.dispose()
+    renderer.domElement.remove()
+  }
+}
+
+onMounted(() => {
+  initScene()
+})
+
+onBeforeUnmount(() => {
+  cleanup()
+})
+</script>
+
+<template>
+  <div ref="containerRef" class="viewport"></div>
+</template>
+
+<style scoped>
+.viewport {
+  width: 100%;
+  height: 100%;
+  overflow: hidden;
+}
+</style>
diff --git a/src/style.css b/src/style.css
index f69131543..28e960fc6 100644
--- a/src/style.css
+++ b/src/style.css
@@ -24,10 +24,7 @@ a:hover {
 
 body {
   margin: 0;
-  display: flex;
-  place-items: center;
-  min-width: 320px;
-  min-height: 100vh;
+  overflow: hidden;
 }
 
 h1 {
@@ -59,10 +56,8 @@ button:focus-visible {
 }
 
 #app {
-  max-width: 1280px;
-  margin: 0 auto;
-  padding: 2rem;
-  text-align: center;
+  width: 100%;
+  height: 100vh;
 }
 
 @media (prefers-color-scheme: light) {
diff --git a/vite.config.ts b/vite.config.ts
index 033620ec7..416e6a81a 100644
--- a/vite.config.ts
+++ b/vite.config.ts
@@ -1,5 +1,4 @@
-/// <reference types="vitest" />
-import { defineConfig } from 'vite'
+import { defineConfig } from 'vitest/config'
 import vue from '@vitejs/plugin-vue'
 
 // https://vite.dev/config/