how to centre h1 in css code example

Example 1: center h1 css

h1 {
    width:500px;
    margin: 0 auto;
    background: gray;
    text-align: center;
}

Example 2: how to center text in css

.class {
	text-align: center;
}

Example 3: html move h1 to center

div{
  height: 400px;
  width: 800px;
  background: red;
  display: flex;
  flex-direction: column;
  justify-content: center;
  text-align: center;
}