<!DOCTYPE html>
<html>
<head>
<title>Title of the document</title>
<style>
div {
width: 150px;
height: 150px;
padding: 15px;
}
.one,
.two,
.three {
position: fixed;
}
.one {
background: #a7b5aa;
outline: 2px solid #000;
top: 100px;
left: 200px;
z-index: 10;
}
.two {
background: #4b48db;
outline: 2px solid #000;
top: 50px;
left: 75px;
z-index: 100;
}
.three {
background: #1ba13f;
outline: 2px solid #000;
top: 30px;
left: 25px;
z-index: 150;
}