Build Blender in the browser. A working 3D modeling and animation app (Three.js), single page, that looks and feels like Blender: dark Blender-style UI with top menu bar, left toolbar, 3D viewport with grid and axis gizmo, Outliner and Properties panels on the right, and a timeline at the bottom. Orbit, pan and zoom with the mouse, numpad-style view buttons. Add > Mesh menu with cube, UV sphere, cylinder, cone, torus and a Suzanne-like monkey head. Click to select with orange outline, G/R/S hotkeys and a transform gizmo to move, rotate and scale, X to delete, Shift+D to duplicate. Properties panel edits transform values and material (base color, roughness, metallic, emission). Insert keyframes with I, scrub the timeline and press play to animate. A Render button (F12) opens a render window with soft shadows and nice lighting. Start with a default scene: cube, camera and light. It should feel like the real thing the moment it loads.