align-self

The align-self property is used for customizing the position of a specific flex item (a child element) along the cross axis of the flex container. The cross axis is typically the vertical axis unless you set column or column-reverse in the flex-direction property. We'll provide our explanation based on the default flex-direction setting.

Unlike other flex box-related properties, this property is set at a child element.

flex-start

With this property value, the selected flex item is positioned at the top edge of the parent element with its original size.

Note: 'edge' means the endpoint with some distance from the edge of the element based on the container's padding and flex item's margin.

align-self: flex-start

center

With this property value, the selected flex item is positioned in the center of the parent element with its original size.