Design language

Canvas

31×29 units centred on (15.5, 12.5), with four keylines: a 23-unit circle, a 20.6 square, a 23×18.4 landscape and an 18.4×23 portrait. Icons are centred, not bottom-aligned.

Layers

Every icon has at least two layers: a mid-tone back piece with a drop shadow, optional white content, and a lighter front piece with a soft top highlight. The top corners of the front piece are rounded separately, exposing the back at the corners.

Outlines and corners

Outlines are 1 unit wide and sit outside the fill. Corner radius is 2.2 for bodies (3.2 with the outline) and 1.2 for content. A coloured band inside an outline is at least 2 units wide, or is omitted.

Colour

Every colour is defined against a reference blue and moved to the accent by relative lightness. Marks are white on mid-tone bodies and deep on light pieces.

Marks

Three weights: 1.6 for content lines, 2.2 for directional marks, 1 for outlines. Minimum element size is 2.4 units. Arrowheads are solid triangles.

Motion

Two keyframes, rest and hover, over 460ms. Motion reproduces the action of the object (a folder opens, an envelope unseals, a calendar turns a page) and is never a metaphor.

The complete rules are in PROMPT.md (Simplified Chinese).