<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
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<html lang="pt-BR">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
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<title>Responsive Nav</title>
</head>
<body>
<header>
<figure class="brand">Responsive</figure>
<nav class="menu">
<input type="checkbox" id="menuToggle">
<label for="menuToggle" class="menu-icon"><i class="fa fa-bars"></i></label>
<ul>
<a href="http://stackoverflow.com/questions/9191803/why-does-z-index-not-work"><li>Home</li></a>
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</header>
</body>
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