center elements vertically in div

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

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

1// example 1 
2div { display: grid; place-items: center; }
3
4// example 3
5div{ display:flex; align-items:center; }
6
7// example 3
8div { width: 100%; margin: 0 auto; }