<!DOCTYPE html>
<html>
<head>
<title>Title of the document</title>
<style>
.outer {
position: relative;
width: 40%;
height: 120px;
margin: 20px auto;
border: 2px solid #468a4d;
}
.inner {
position: absolute;
width: 100px;
height: 100px;
top: 10px;
left: 50%;
margin-left: -50px;
background-color: #1703fc;
}
</style>
</head>
<body>
<div class="outer">
<div class="inner"></div>
</div>
</body>
</html>