This example shows an animated sunrise and sunset over a stylized mountain landscape, using purely declarative SVG markup. The sky and two layered terrain paths transition through a daily color cycle via `<animate>` elements on radial and linear gradients, while the sun circles vertically between the mountains and horizon. The piece demonstrates core SVG fundamentals—shapes, paths, gradients, and declarative animation—without relying on JavaScript or external libraries, and explicitly defines its geometry and timing in the document itself.