flex-flow is a shorthand for flex-direction and flex-wrap, letting one declaration control both the direction and wrapping behavior of flex items. section 4.4.1
Wrap items into columns
Use flex-flow: column wrap to flow items from top to bottom and wrap them into a new column when necessary. Column wrapping requires a constrained container height; otherwise, the container grows to contain its items. section 4.4.1
The wrapping component of flex-flow follows these rules:
- nowrap is the initial value; wrap and wrap-reverse allow items to move onto additional lines. section 4.4.1
- When wrapping is enabled, items that would overflow move to a new line instead of shrinking according to flex-shrink. section 4.4.1
