MockupWindow(
  style: [BorderUtil.border, BorderUtil.base300, Size.wFull],
  [
    Container(
      [text('Hello!')],
      style: [Layout.grid, Alignment.placeContentCenter, Size.h(80)],
      // The top border on the content is part of the content's style.
      // Use `classes` for specific utilities like directional borders.
      classes: 'border-t border-base-300',
    ),
  ],
)

MockupWindow(
  style: [
    BgUtil.base300,
    BorderUtil.border,
    BorderUtil.base300,
    Size.wFull,
  ],
  [
    Container(
      [text('Hello!')],
      style: [Layout.grid, Alignment.placeContentCenter, Size.h(80)],
      // The background color of the content is separate from the window frame.
      classes: 'bg-base-200',
    ),
  ],
)