Effects, masks, and composite
Ordered operators
Effects are explicit operators evaluated in order. The order is part of the visual meaning.
{
"effects": [
{ "type": "blur", "radius": 24 },
{ "type": "drop-shadow", "offset": { "x": 18, "y": 20 }, "blur": 16, "color": "#000000", "opacity": 0.25 }
],
"composite": { "opacity": 1, "blendMode": "normal" }
}
Masks
Clip, alpha, inverse-alpha, luma, nested masks, and isolation describe coverage relationships. They are not high-level layout features.
Paint and composite opacity
Fill opacity and stroke opacity belong to their paint sources. Layer/composite opacity belongs to the composite result. Keeping them separate makes effect and export behavior predictable.
Static teaching boundary
The figures in the web guide are explanatory pictures. They do not execute an offscreen pass or initialize a graphics API.