of the center by 20% horizontally <center> code example

Example 1: center a div in css

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

Example 2: center with css

.parent {
  position: relative;
}
.child {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

Example 3: 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*/
}