URL_WEB:https://perk-bevis.github.io/Flex_Box/
reference first: https://css-tricks.com/snippets/css/a-guide-to-flexbox/?fbclid=IwAR3FrDxYega_xoGQTzY9aeYnzoImivNx2UW_RWJHGw04gRdUnydOXXT8418#aa-background
reference second:https://codepen.io/enxaneta/full/adLPwv/?fbclid=IwAR0Pz6eUjOXcUaHjCzSHTDlDaNWsqhqAGWqMmVX0nWktnlC3NmL6PgDJodU