justify-item:center in display grid code example

Example 1: justify content vs align items gridd

The justify-content and align-content properties align the grid.

The justify-self, justify-items, align-self and align-items properties align the grid items.

Example 2: align items center in grid

article {
  display: inline-grid;
  grid-template-rows: 100px 100px 100px;
  grid-template-columns: 100px 100px 100px;
  grid-gap: 3px;
}

section {
  display: flex;
  justify-content: center;
  align-items: center;
  border: 2px solid black;
  font-size: 3em;
}