A **panel** which splits horizontally the contained panels into multiple columns of the same size (if possible). ```jsx import Bluelib from "../Bluelib"; import Box from "../Box"; 1 / 1 1 / 2 2 / 2 1 / 3 2 / 3 3 / 3 1 / 4 2 / 4 3 / 4 4 / 4 ```