Edit in JSFiddle

<html>
    <head>
        <title>Shows child element overlapping the parent element's container. Also shows background covering half of the parent element</title>
    </head>
    <body>
        <p class="lol">BLAH BLAH BLAH</p>
        <div>
            <em>1</em>
            <section>
                <h1>Header of a section</h1>
                <p>Section paragraph. The background color is in the section, which extens out through negative margins and positive padding. The negative top margin pulls the element up, while the padding-top produces extra background.</p>
            </section>
        </div>
    </body>
</html>
.lol{
    background: #000;
    margin: 0;
    height: 100px;
    color: #fff;
}
em{
    margin-top: -30px;
    display: block;
    font-size: 40px;
    color: #151;
}
h1{
    margin: 0;
}
section{
    background: #ccc;
    margin-top: -20px;
    padding: 20px;
}