重要属性
flex-direction
flex-wrap
flex-flow
justify-content
align-items
align-content
其他属性
order
flex-grow
flex-shrink
flex-basis
flex
align-self
flex-direction
flex-wrap
flex-flow
justify-content
align-items
align-content
order
flex-grow
flex-shrink
flex-basis
flex
align-self