Background Color / Pattern: Classic theme — overlay colour and 10 predefined pattern styles.
Popup Background / Text Color: Panel colours for both themes.
Modern Popup Design: When Modern theme is active — width, max height, viewport margin, corner radius, overlay blur, accent colour, title/subtitle sizes.
Modern Buttons: Pill (2026), rounded, or outline styles; side-by-side or stacked layout.
Motion Effects: Full animate.css library (30+ effects) or built-in Modern zoom/fade/slide when Motion Effect is None.
Animation Duration: Slow, slower, fast, or faster when using animate.css.
