New style template: Neumorphism

The style gallery grew by one: Neumorphism, the 2019-2020 "soft UI" look where every button, card and toggle is molded from a single base color and separated from the background only by a paired light and dark shadow - a raised dial with a colored progress arc, a pressed segmented control, and switches built from an inset track and a raised knob.

It shares its sense of soft depth with Glassmorphism and Lightweight 3D, but gets there with shadow alone - no blur, transparency or gloss - and it is the mirror image of Brutalism's hard borders. Because the effect depends on the background, the template recalculates its highlight and shadow from your palette's background color: near-white highlights on a light base, and only slightly lighter ones on a dark base. The accent color is kept for active states, where a same-color surface needs a clear signal.