flex align box center code example

Example 1: css flex center

display: flex;
align-items: center;
justify-content: center;

Example 2: flex box align items

.container {
  justify-items: center;
}

Example 3: center flex

.flex-container {
  display: flex;
  height: 300px;
  justify-content: 
  center;
  align-items: center;
}