What is flexbox?

CSS 2.1 defined four layout modes

Flex layout is designed for laying out more complex applications.

The main purpose of a flex container is to expand items to fill available free space, and conversely shrink them to prevent overflow. It can also be used to change visual ordering both horizontally and vertically.

What can it do?

Where can I use it?

Flexbox is now widely supported by all modern browsers.