An animated sunrise and sunset scene in pure SVG. The sky’s radial gradient and the two layered landscape paths shift from aliceblue to indigo and steelblue, while a yellow sun circle moves vertically between 250px and 350px using `<animate>`. The gradients use `<stop>` elements with `attributeName` animations, and the land paths are drawn with cubic and quadratic Bézier curves. The composition cycles indefinitely over 15 seconds, simulating a day-night transition.