Make one HTML file: a 10-second looping animation of a dinosaur scene. Long-necked dinosaurs wade across a misty river at sunrise, birds lift off the water, and at the end a T-rex steps out of the jungle and roars. Draw everything in code (SVG or canvas). No images, no external libraries, no network requests. It should look like the opening shot of a nature documentary, not clip art. Write it in one go: don't open it in a browser, render it or test it. Just deliver the file.