form.rb

<div class="row">
	<div class="col l12">
		<p class="signup-header">Join today</p>
	</div>
</div>

<div class="row signup-form">

	<%= form_for @user do |f| %>
		<div class="row">
			<div class="col l8">
			  <%= f.label :first_name %>:
			  <%= f.text_field :first_name %><br />
			</div>
		</div>

		<div class="row">
			<div class="col l8">
			  <%= f.label :last_name %>:
			  <%= f.text_field :last_name %><br /> 
			</div>
		</div>

		<div class="row">
			<div class="col l8">
			  <%= f.label :email %>:
			  <%= f.text_field :email %><br />
			</div>
		</div>

		<div class="row">
			<div class="col l8">  
			  <%= f.label :password %>:
			  <%= f.password_field :password %><br />
			</div>
		</div>

		<div class="row">
			<div class="col l8">
			  <%= f.submit 'Sign Up' %>
	  	</div>
		</div>

	<% end %>

</div>

style.css

/* SIGN UP */

.signup-header{
	font-size: 3em;
	text-align: center;
}
.signup-form{
	padding-top: 5%;
	padding-left: 25%;
	padding-right: 10%;
}