Turn a 2D blueprint into a 3D walkthrough you can tour, as one HTML file. First draw the blueprint yourself: a two-bedroom apartment of about 80 m² (entry, open living room with kitchen, two bedrooms, one bathroom, a balcony) on blueprint paper, with walls, doors, windows, room names and dimensions. Then turn that exact plan into 3D: the walls rise out of the drawing, floors, doors, windows and simple furniture appear, and the camera walks in through the front door at eye height and tours every room. It should play by itself in about 20 seconds when the page opens, then let me look around, walk with the keyboard, or replay. Make it one HTML file that opens offline in a browser: no CDN links and no network requests. If you use a library like Three.js, put it inside the file. No image files, no image or video models.