<!doctype html>
<html>
    <head>
        <meta charset="utf-8">
    </head>
    <body>
        <style>
            #black {
                background-color: black;
                height: 50px;
                position: relative;
                width: 25px;
            }
            #grey {
                background-color: grey;
                position: relative;
                width: 25px;
                height: 50px;
                left: 25px;
                top: -50px;
            }
        </st