<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" />
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<title>CodePen - grid images</title>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/meyer-reset/2.0/reset.min.css">
<style>
.grid {
max-width: 1180px;
width: 100%;
margin: 0 auto;
background: red;
height: 885px;
font-size: 0;
}
.grid .coll {
font-size: 12px;
max-width: 25%;
width: 100%;
display: inline-block;
vertical-align: top;
height: 100%;
background: #606060;
}
.grid .coll .square {
height: 295px;
width: 100%;
background: #bbb;
