how to center a header with css code example

Example 1: css position element in the middle of a header

P.blocktext {
    margin-left: auto;
    margin-right: auto;
    width: 200px;/*usually works best with a fixed width*/
}

Example 2: how to horizontally center header at the top of page with flexbox css

.box.flex {
  display: flex;
  justify-content: center;
}