Flexbox is a one-dimensional layout method, which means it is designed to arrange items in one direction at a time—either as a row or as a column. Even when items are set to wrap onto multiple lines, each flex line acts like a new, independent flex container. Consequently, it is not possible to align an item in one row with an item in another row; for control over both rows and columns simultaneously, a two-dimensional system like CSS Grid is required.
flex-direction property; if the direction is set to row, the main axis runs horizontally, and if set to column, it runs vertically.order, row-reverse, and column-reverse change how items appear on the screen without changing the underlying HTML source. This is problematic because screen readers and keyboard navigation (tabbing) follow the source code order, which can confuse users if the focus jumps around the screen in a non-linear fashion.justify-content.