<!DOCTYPE html>
<html lang="en">
<head>
<title>Bootstrap Example</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/js/bootstrap.min.js"></script>
<style>
body {
position: relative;
}
.affix {
top: 20px;
z-index: 9999 !important;
}
div.col-sm-9 div {
height: 250px;
font-size: 28px;
}
#section1 {color: #fff; background-color: #1E88E5;}
#section2 {color: #fff; background-color: #673ab7;}
#section3 {color: #fff; background-color: #ff9800;}
#section41 {color: #fff; background-color: #00bcd4;}
#section42 {color: #fff; background-color: #009688;}
@media screen and (max-width: 810px) {