div align center

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

1<div class="container">
2  <div class="child"></div>
3</div>
4.container {
5  ...
6  display: flex;
7  justify-content: center;
8  align-items: center;
9}

1.center {
2  display: block;
3  margin-left: auto;
4  margin-right: auto;
5}

1.MyDiv{
2  	display: block;
3  	margin-left: auto;
4	margin-right: auto;
5}

1.parent {
2  position: relative;
3}
4.child {
5    position: absolute;
6    left: 50%;
7    top: 50%;
8    transform: translate(-50%, -50%);
9}

1.center {
2  text-align: center;
3}
4
5// or
6
7<div style="text-align:center">
8</div>