In this link of the tutorial that you passed in the question it shows the answer, see the HTML code again:
<html>
<head>
<meta charset="utf-8">
<title>Meus Contatos</title>
<meta name="description" content="">
<meta name="viewport" content="width=device-width">
<link rel="stylesheet" href="public/libs/bootstrap/dist/css/bootstrap.css"/>
<link rel="stylesheet" href="public/styles/style.css"/>
</head>
<body>
<div class=login-page>
<div class=row>
<div class="col-md-4 col-lg-4 col-md-offset-4 col-lg-offset-4">
</br>
</br>
</br>
</br>
</br>
</br>
</br>
</br>
<h1>Sistema Teste<small> versão 1.0</small></h1>
<form role=form ng-submit=submit()>
<div class=form-content>
<div class=form-group> <input type=text class="form-control input-underline input-lg" placeholder=Email> </div>
<div class=form-group> <input type=password class="form-control input-underline input-lg" placeholder=Password> </div>
</div>
<button type=submit class="btn btn-white btn-outline btn-lg btn-rounded">Login</button>
</form>
</div>
</div>
</div>
</body>
<html>
See the class that it is assigning to the input, input-underline
, which belongs to the default bootstrap style sheet and lets you leave the input field with this style, just one line down instead of that standard HTML box:
<input type=text class="form-control input-underline input-lg" placeholder=Email>
This code is using the Framework Twitter Bootstrap as you can see the statement below:
<link rel="stylesheet" href="public/libs/bootstrap/dist/css/bootstrap.css"/>
Take a look at this Framework! It is very good to start developing simple and multi-responsive systems!
Then I advise you to start developing your own web systems in the format MVC with Zend, CodeIgniter, CakePHP or another Framework that suits you.
Because your work will have more credibility and organization than a system developed in pure PHP or JQuery!
Good luck with college my friend!
I hope I have helped ^^