Learning flexbox

Issue #62

CSS

• body height https://www.kirupa.com/html5/make_body_take_up_full_browser_height.htm

Flexbox

• Properties of flex https://codepen.io/enxaneta/full/adLPwv
• Visual guide to flexbox https://scotch.io/tutorials/a-visual-guide-to-css3-flexbox-properties
• align-items vs align-content https://stackoverflow.com/questions/27539262/whats-the-difference-between-align-content-and-align-items
• align-items vs justify-content https://stackoverflow.com/questions/35049262/difference-between-justify-content-vs-align-items
• multiple line https://stackoverflow.com/questions/41789278/first-child-full-width-in-flexbox