justify-content = main axis
align-items = cross axis
align-content = cross axis with wrap; to be used when weird gap appear between rows/columns
photo gallery: grid-template-columns: repeat(auto-fit, minmax(154px, 1fr));
justify-items: align items on the horizontal axis
align-items: align items on the vertical axis
if (if grid items don't take all the space of the grid, add a border to the grid to check) { justify-content: align the grid itself on the horizontal axis
align-content: align the grid itself on the vertical axis }