Main Content
This is the main area. Because it uses a larger flex value, it becomes wider than the sidebars and takes up most of the row.
This is the main area. Because it uses a larger flex value, it becomes wider than the sidebars and takes up most of the row.
All three boxes share the available width equally.
Flex 1 on each item creates equal-width columns.
Flexbox also keeps the column heights consistent.