The other CSS terms for this are block and inline, as in padding-inline-start and padding-block-end. Whether it’s the top/bottom/left/right edge is determined by flow direction. iOS/SwiftUI calls the inline directions leading and trailing, but I’m not sure how it works with vertical type
Technically, block and inline dimensions are defined with respect to the direction of the text. The terms used in the CSS spec to refer to the direction of justify-content and align-items are the main axis and the cross axis, respectively.
