index.html

<!DOCTYPE html>
<html>
<head>
    <title>Shell Sort</title>
    <meta charset="utf-8" />
    <link rel="stylesheet" href="css/style.css" />
</head>
<body>

    <h1 class="head-title">Shell Sort</h1>

    <form class="form-sort">
        <input type="text" id="f-1" />
        <input type="text" id="f-2" />
        <input type="text" id="f-3" />
        <input type="text" id="f-4" />
        <input type="text" id="f-5" />
        <input type="text" id="f-6" />
        <input type="text" id="f-7" />
        <input type="text" id="f-8" />
        <input type="text" id="f-9" />
        <input type="text" id="f-10" />
        <span class="form-more"> + </span>
        <span class="form-btn">
            <button type="button" class="btn">Sort</button>
        </span>
    </form>

<script type="text/javascript" src="js/main.js"></script>
</body>
</html>