Horizontally and vertically centers a child element within a parent element using grid.

<div class="grid-centering"><div class="child">Centered content.</div></div>

.grid-centering {
  display: grid;
  justify-content: center;
  align-items: center;
  height: 100px;
}

Explanation

1. display: grid enables grid.
2. justify-content: center centers the child horizontally.
3. align-items: center centers the child vertically.

Browser support

• https://caniuse.com/#feat=css-grid