How can flex items be distributed inside a flex container in the cross axis direction?

The CSS align-items property sets the align-self value on all direct children as a group. In Flexbox, it controls the alignment of items on the Cross Axis. In Grid Layout, it controls the alignment of items on the Block Axis within their grid area.

/* Basic keywords */
align-items: normal;
align-items: stretch;

/* Positional alignment */
/* align-items does not take left and right values */
align-items: center; /* Pack items around the center */
align-items: start; /* Pack items from the start */
align-items: end; /* Pack items from the end */
align-items: flex-start; /* Pack flex items from the start */
align-items: flex-end; /* Pack flex items from the end */

/* Baseline alignment */
align-items: baseline;
align-items: first baseline;
align-items: last baseline; /* Overflow alignment (for positional alignment only) */
align-items: safe center;
align-items: unsafe center;

/* Global values */
align-items: inherit;
align-items: initial;
align-items: unset;

Source: https://developer.mozilla.org/en-US/docs/Web/CSS/align-items