The CSS align-items property aligns flex items of the current flex line the same way as justify-content but in the perpendicular direction.
The cross-start margin edge of the flex item is flushed with the cross-start edge of the line.
The cross-end margin edge of the flex item is flushed with the cross-end edge of the line.
The flex item’s margin box is centered within the line on the cross-axis. If the cross-size of the item is larger than the flex container, it will overflow equally in both directions.
All flex items are aligned such that their baselines align. The item with the largest distance between its cross-start margin edge and its baseline is flushed with the cross-start edge of the line.
Flex items are stretched such as the cross-size of the item’s margin box is the same as the line while respecting width and height constraints.