<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<link rel="shortcut icon" type="image/x-icon" href="https://static.codepen.io/assets/favicon/favicon-aec34940fbc1a6e787974dcd360f2c6b63348d4b1f4e06c77743096d55480f33.ico" />
<link rel="mask-icon" type="" href="https://static.codepen.io/assets/favicon/logo-pin-8f3771b1072e3c38bd662872f6b673a722f4b3ca2421637d5596661b4e2132cc.svg" color="#111" />
<title>CodePen - Minimal image gallery with thumbnails</title>
<style>
.simple-gallery {
width: 408px;
display: block;
margin: auto;
margin-top: 50px;
box-shadow: 5px 20px 60px 10px Gray;
}
img {
border-top: 1px solid Gainsboro;
border-left: 1px solid Gainsboro;
}
.mini img {
width: 98px;
height: 98px;
float: left;
margin: 4px 4px 0px 0px;
cursor: pointer;
}
.mini img:nth-of-type(4) {
