fixed header on scroll html 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: fixed navigation menu

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  height: 1200px;
  font-size: 18px;
  font-family: sans-serif;
  color: #5D6063;
}

a:link,
a:visited {
  color: #5D6063;
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}

.header {
  position: fixed;
  display: flex;
  justify-content: space-between;
  
  width: 100%;
  padding: 50px;
  background: #D6E9FE;
}