Hairline
すべての形を、ごく細い線で囲む。
視覚的特徴
- どの形にも、画面幅の約0.25%（幅600pxで1.5px）の細い輪郭線がある
- 線の太さは一定
- 線は境界がわかる最小限の太さ
Hairline outlines: trace every shape with a very thin, uniform line (about 0.25% of the frame width), just enough to define the edge.
bold outlines, thick strokes, variable line weight, no outlines