Bottom fixed div problem

HTML

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<style>
    body {
        margin: 0;
        padding: 0;
    }
    .example {
        width: 100vw;
        height: 100vh;
        background: url('http://dpanoply.s3.amazonaws.com/blog/9-best-sites-for-free-stock-photos/pexels.jpg');
        background-size: 100% 100%;
    }
    .example > .toolbar {
        width: 100vw;
        height: 60px;
        background-color: #b1b1b1;
        border-top: 1px solid #3b3b3b;
        text-align: center;
        font-size: 11px;
        position: fixed;
        bottom: 0;
    }
</style>
<body>
    <div class="example">
        <div class="toolbar">
            <h1>TOOLBAR</h1>
        </div>
    </div>
</body>
</html>