// Padding / gap / radius accept 1-, 2-, or 4-value forms (SPEC section 6).
{
|scene| layout:column gap:12 padding:(4, 8)
--radius:6
}
|rect| "scalar padding" size:(200, 30)
|rect| "(y, x) padding" size:(200, 30) padding:(4, 12)
|rect| "(t, r, b, l)" size:(200, 30) padding:(2, 8, 16, 24)
|rect| "radius scalar:8" size:(200, 30) radius:8
|rect| "radius (top,bot)" size:(200, 30) radius:(2, 20)
inner |group| "(2,8,16,24) gap demo" layout:column gap:(4, 8) padding:(2, 8, 16, 24) {
|rect| size:(80, 20); |rect| size:(80, 20); |rect| size:(80, 20)
}