--- root: items: - type: stacking-context bounds: [0, 0, 50, 50] items: - type: border bounds: [ 0, 0, 50, 50 ] width: [ 10, 10, 10, 10 ] border-type: gradient start: [ 25, 0 ] end: [ 25, 50 ] stops: [ 0.0, red, 1.0, green ] outset: [ 0, 0, 0, 0 ]