css vertical align items in div

1/* this will center all children within the parent element. */
2.parent {
3  display: flex;
4  justify-content: center; /* horizontal */
5  align-items: center; /* vertical */
6}

1.parent {
2  display: flex;
3  justify-content: center;
4  align-items: center;
5}

1.flex-center-vertically {
2  display: flex;
3  justify-content: center;
4  flex-direction: column;
5  height: 400px;
6}

1.top-align {
2	vertical-align: top;
3}  
4
5.center-align {
6  	vertical-align: middle;
7}