A little piece of sunlight

Build 'A little piece of sunlight' for an invented Sampleton Observatory. Make an original illustrated journey with four stops: Within the star, Into open space, Across the dark and At the blue edge. Draw stellar layers, a travelling point of light, open space and a stylised Earth and atmosphere. Clearly disclose that distance and time are compressed and the Earth is stylised; this is a visual story, not a scientific simulation. Offer a Journey slider, Take the journey and direct stop buttons, with Play, Pause, Reset and Keep the horizon as PNG. Keep it silent. Fit each scene completely inside the available popup or full page canvas without cropping. Retain native controls and text of at least 12px, allow the controls to scroll on narrow screens and start on a still scene for reduced motion.

1. Use one progress value for the four scenes, their captions and light position. Define explicit stop values so each part of the story is directly reachable.
2. Draw the original star layers, space and stylised Earth from that progress, keeping composition and transitions deterministic when scrubbing backwards.
3. Make manual scrubbing or a stop choice hold the journey. Take the journey restarts automatic progress, while Pause freezes the current scene.
4. Contain the full composition at each viewport size and keep the scale disclaimer in readable HTML beside the controls. Offer the selected horizon or star scene as a PNG.
5. Start without travel under reduced motion and retain access to every stop as a still. Remove the frame loop when the plate leaves view or unmounts.