redered.html

<h1>Login</h1>
<form action="/login" accept-charset="UTF-8" method="post">
  <input name="utf8" type="hidden" value="&#x2713;" />
  <input type="hidden" name="authenticity_token" value="AqKKkvrqHt0Ti5LmfK8Ti6Bkj67ctsM9bUrlahEsPhhzeIDVn61SwoWB1jt0funAiU/X4Uu5E1mpiFnb509jeQ==" />
  Senha: <input type="password" name="password" id="id" class="classe" /><br>
  <input type="submit" name="commit" value="Prosseguir" class="message-btn" id="send-mail" />
</form>
<a href="/">Voltar</a>
<a href="/admin/login">Administração</a>

template.erb

<h1>Login</h1>
<%= form_tag ({controller: 'web/sessions', action: 'create'}) do %>
  Senha: <%= password_field_tag(:password, nil, class: 'classe', id: 'id') %><br>
  <%= submit_tag 'Prosseguir', class: 'message-btn', id: 'send-mail' %>
<%end%>
<%= link_to 'Voltar', '/' %>
<%= link_to 'Administração', new_admin_user_session_path %>