How grid items can be aligned in their own cells?

/* Basic keywords */
justify-self: auto;
justify-self: normal;
justify-self: stretch;

/* Positional alignment */
justify-self: center;     /* Pack item around the center */
justify-self: start;      /* Pack item from the start */
justify-self: end;        /* Pack item from the end */
justify-self: flex-start; /* Equivalent to 'start'. Note that justify-self is ignored in Flexbox layouts. */
justify-self: flex-end;   /* Equivalent to 'end'. Note that justify-self is ignored in Flexbox layouts. */
justify-self: self-start;
justify-self: self-end;
justify-self: left;       /* Pack item from the left */
justify-self: right;      /* Pack item from the right */

/* Baseline alignment */
justify-self: baseline;
justify-self: first baseline;
justify-self: last baseline;

/* Overflow alignment (for positional alignment only) */
justify-self: safe center;
justify-self: unsafe center;

/* Global values */
justify-self: inherit;
justify-self: initial;
justify-self: unset;

/* Keyword values */
align-self: auto;
align-self: normal;

/* Positional alignment */
/* align-self does not take left and right values */
align-self: center; /* Put the item around the center */
align-self: start; /* Put the item at the start */
align-self: end; /* Put the item at the end */
align-self: self-start; /* Align the item flush at the start */
align-self: self-end; /* Align the item flush at the end */
align-self: flex-start; /* Put the flex item at the start */
align-self: flex-end; /* Put the flex item at the end */

/* Baseline alignment */
align-self: baseline;
align-self: first baseline;
align-self: last baseline;
align-self: stretch; /* Stretch 'auto'-sized items to fit the container */

/* Overflow alignment */
align-self: safe center;
align-self: unsafe center;

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