campo buscar

<div class="login-box">
                    <div class="form-busca form-busca-off">
                        <form class="form-busca-site" action="">
                            <input class="btn-text-top" type="text" name="txtsearch" placeholder="Buscar">
                            <button class="btn-buscar-top" type="submit"></button>
                        </form>