<!DOCTYPE html>
<html>
<style>
body {
  margin: 0;
  height: 4000px;
  overflow: hidden;
}
div {
  background: blue;
  width: 200px;
  height: 200px;
  margin-top: 300px;
  position: sticky;
  bottom: 100px;
}
</style>
<div></div>