Splits inside a split: the wall is a vertical split of rows, each row a split of its own. Drag the edge under this row to give it more height, or the one beside this tile for more width.

Every tile names a floor, `zone--min-*`: below it the tile is not squeezed, the frame scrolls instead — sideways as well as down.

Resized, a zone keeps the size it was left at along its split's axis, and comes back with it; a double click on the handle gives it back to the split.

`zone--split--flush` narrows the gap to a pixel, the wall's ground drawing the line between tiles. One class on the wall is enough, the rows inherit it.

Without it the same wall keeps the room between its tiles, through which the page's ground shows — switch in the bar above. Scroll right for a panel loaded only once it is seen.