<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<style>
*{
margin: 0;
padding: 0;
}
.right{
position: absolute;
100px;
height: 100px;
background: pink;
right: 0;
opacity: 0.5;
}
.left{
height: 100px;
background: #123;
margin-right: 100px;
}
</style>
</head>
<body>
<div class="right"></div>
<div class="left"></div>
</body>
</html>