index.html

<!DOCTYPE html>
<html>

<head>
    <meta http-equiv="Content-Type" content="text/html;charset=utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=no">


    <title>Todo list app</title>

    <link href="https://fonts.googleapis.com/css?family=Roboto:400,500,700" rel="stylesheet">
    <link rel="stylesheet" type="text/css" href="assets/css/reset.min.css">
    <link rel="stylesheet" type="text/css" href="assets/css/style.css">
</head>

<body>

    <header>
        <input type="text" placeholder="Enter an activity.." id="item">
        <button id="add">+</button>
    </header>

    <div class="container">
        <ul class="todo" id="todo"></ul>

        <ul class="todo" id="completed"></ul>
    </div>

    <script src="assets/js/main.js"></script>
</body>

</html>