Flexbox: Lining Things Up in a Row or a Column

One line of CSS, display: flex, lines up an element's children in a row, flex-direction turns the row into a column, and the main and cross axes name the two directions every other flexbox property works along.

Updated

Cheat sheet: Flexbox: Lining Things Up in a Row or a Column
Category
CSS
Level
Apprentice
Tags
Cross axis, CSS, Flex container, Flex direction, Flex item, Flexbox, Main axis