<div class="container">
    <div class="row">
        <form>
            <div class="col-sm-8">
                <input type="text" placeholder="Enter your e-mail" spellcheck="false">
            </div>
            <div class="col-sm-4">
                <button class="btn btn-lg btn-primary" type="submit">
                    Join newsletter
                </button>
            </div>
        </form>
    </div>
</div>