http://www.w3.org/TR/css3-flexbox/#justify-content-property

Check the box or focus (not hover) the link to switch flex direction.

switch direction
  1. [#l01] List item 1
  2. List item 2
  3. List item 3
  1. [#l02] List item 1
  2. List item 2
  3. List item 3
  1. [#l03] List item 1
  2. List item 2
  3. List item 3
  1. [#l04] List item 1
  2. List item 2
  3. List item 3
  1. [#l05] List item 1
  2. List item 2
  3. List item 3
  1. [#l06] List item 1
  2. List item 2
  3. List item 3