header follow scroll css code example

Example 1: how to scroll fixed position

.fixed-content {
    top: 0;
    bottom:0;
    position:fixed;
    overflow-y:scroll;
    overflow-x:hidden;
}

Example 2: html how to ensure that the header always on top

#header {
  position: fixed;
}

#content {
  margin-top: 100px;
}