type: rect

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A rectangle: a pure decoration box painted by the unified Style — the same backgroundColor / borderWidth / borderColor / borderStyle / opacity keys every other item uses, including named styles via styleNames. rect has no content, so padding and all text-level style keys are ignored (inert keys on the inline style warn shape_style_ignored); it needs explicit w/h.

Nothing draws unless a style layer authors it: a bare rect is invisible (there is no implicit default stroke). Author borderWidth for an outline, backgroundColor for a fill.

Syntax

- type: rect
  box: { x: 0, y: 0, w: 200, h: 40 }   # w/h required (rect_missing_size)
  styleNames: [panel]                   # named styles, like any item
  style:
    borderWidth: { bottom: 2 }   # scalar or per-side map, pt; unset = none
    borderColor: "#333333"       # scalar or per-side; unset side = black
    borderStyle: double          # solid (default) | double | dashed | dotted
    borderRadius: 6              # rounds the corners (uniform borders only)
    backgroundColor: "#f7f7f7"   # fill, default none
    opacity: 0.5                 # 0..=1 paint alpha, default 1 (opaque)

Keys

Key	Type	Default	Description
box	map	required	Position and size (box.md); margins work, padding is ignored.
styleNames	list	—	Named styles from the styles: registry, layered below the inline style.
style.*	Style decoration subset	—	backgroundColor, borderWidth, borderColor, borderStyle, borderRadius, opacity. A side draws iff its computed width > 0. Text keys are inert and warn shape_style_ignored.

The retired shape-style spelling fillColor is a located parse error — use backgroundColor. Engines without the style.shapes.unified capability key expect the old fillColor wire instead.

Limitations

• box.w/box.h are required (rect_missing_size).
• A rect has no content, so text and box style keys are inert on it (shape_style_ignored).
• borderRadius is a single value for all four corners — there are no per-corner radii — and it is refused on a per-side or double border (border_radius_ignored, invalid_border_radius).

Diagnostics

Code	Meaning
rect_missing_size	box.w/box.h absent
shape_style_ignored	text/box keys on the inline style that have no effect on a rect
invalid_opacity	out-of-range opacity; drawn opaque
invalid_border_width	non-finite or absurd width; no border

Capability keys: rect, style.shapes.unified.

See also

• line.md — a stroked segment (keeps its own width/color style)
• style.md — the shared decoration vocabulary
• form_marks.md — ellipse/checkbox (same Style, 1pt frame default)