Flexbox guide

Snippet for positioning items centered horizontally and vertically:

Snippets for container positioning items and IE10 rules:

Read more here:
css-tricks.com/snippets/css/a-guide-to-flexbox/

Legacy browser support: (E.g. Internet Explorer 10):
https://css-tricks.com/using-flexbox/

Cheatsheet flexbox equiv. for IE10:
https://gist.github.com/Paul-frc/3ed765ed10c9635384e98f58334081e4