now follow the same design pattern (in elliptical-torus.html and rotating_ellipse8.html):

1. the dropdown on top left corner “Geometry” which provide explanation of the design
2. Save PNG feature + its filenaming convention.
3. Saved PNG to displayed past saved PNGs.
4. various slider to allow variations on the graphics drawn being possible.
5. overall dark background (black or dark blue and bright coloured lines as foreground)