Devise login form with form_inline in the navbar - ruby-on-rails

Question

I am trying to make a Devise login form as form_inline in my navbar.
At this point a have made it like this:
Link to picture of the navbar it look like a this point: http://postimg.org/image/i3ka5fsur/
it has the code:
<li><%= form_for(:user, :url => session_path(:user)) do |f| %>
<%= f.text_field :email, :placeholder => "Email" %>
<%= f.password_field :password, :placeholder => "Password" %>
<%= f.check_box :remember_me %><%= f.label :remember_me %>
<%= f.submit 'Login' %>
<% end %></li>
I'm just not quite happy with it's look at this point, I more want it like the form_inline:
Link to picture of the navbar I want it to look like: http://postimg.org/image/7590n949f/
the form_inline code is:
<form class="form-inline">
<input type="text" class="input-small" placeholder="Email">
<input type="password" class="input-small" placeholder="Password">
<label class="checkbox">
<input type="checkbox"> Remember me
</label>
<button type="submit" class="btn">Sign in</button>
</form>
Hope some of you can help me, i'm new a programmering and don't have a lot of experience with programmering.

Answer 1

with twitter bootstrap3
<%= form_for(:user, :url => session_path(:user), html: { class: "navbar-form navbar-right form-inline" }) do |f| %>
<div class="form-group">
<%= f.text_field :email, :placeholder => "Email", class: "form-control" %>
</div>
<div class="form-group">
<%= f.password_field :password, :placeholder => "Password", class: "form-control" %>
</div>
<div class="checkbox">
<%= f.check_box :remember_me %><%= f.label :remember_me %>
</div>
<%= f.submit 'Login', class: "btn btn-default" %>
<% end %>
with twitter bootstrap2
<%= form_for(:user, :url => session_path(:user), html: { class: "navbar-form pull-right form-inline" }) do |f| %>
<%= f.text_field :email, :placeholder => "Email", class: "input-small" %>
<%= f.password_field :password, :placeholder => "Password", class: "input-small" %>
<label class="checkbox">
<%= f.check_box :remember_me %><%= f.label :remember_me %>
</label>
<%= f.submit 'Login', class: "btn" %>
<% end %>

Answer 2

You should include the css that describes form_inline class and input-small class e.t.c
Then in your code you should assign classes to your elements like below
<li><%= form_for(:user, :url => session_path(:user)), :class => "form-inline" do |f| %>
<%= f.text_field :email, :placeholder => "Email", :class => "input-small" %>
<%= f.password_field :password, :placeholder => "Password", :class => "input-small" %>
<%= f.check_box :remember_me, :class => "checkbox" %><%= f.label :remember_me, :class => "checkbox" %>
<%= f.submit 'Login', :class => "btn" %>
<% end %></li>