Kako napraviti registracijsku formu?

U ovome primjeru kreiraćemo jednostavnu formu za registraciju. 



<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
  <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto:400,700">
  <title>IT TUTORIJALI | Registracija</title>
  <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.0/css/bootstrap.min.css">
  <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css">
  <script src="https://code.jquery.com/jquery-3.5.1.min.js"></script>
  <script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.0/dist/umd/popper.min.js"></script>
  <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.5.0/js/bootstrap.min.js"></script>
  <style>
    body {
      color: #fff;
      background: #3598dc;
      font-family: 'Roboto', sans-serif;
    }

    .form-control {
      height: 41px;
      background: #f2f2f2;
      box-shadow: none !important;
      border: none;
    }

    .form-control:focus {
      background: #e2e2e2;
    }

    .form-control,
    .btn {
      border-radius: 3px;
    }

    .signup-form {
      width: 400px;
      margin: 30px auto;
    }

    .signup-form form {
      color: #999;
      border-radius: 3px;
      margin-bottom: 15px;
      background: #fff;
      box-shadow: 0px 2px 2px rgba(0, 0, 0, 0.3);
      padding: 30px;
    }

    .signup-form h2 {
      color: #333;
      font-weight: bold;
      margin-top: 0;
    }

    .signup-form hr {
      margin: 0 -30px 20px;
    }

    .signup-form .form-group {
      margin-bottom: 20px;
    }

    .signup-form input[type="checkbox"] {
      margin-top: 3px;
    }

    .signup-form .row div:first-child {
      padding-right: 10px;
    }

    .signup-form .row div:last-child {
      padding-left: 10px;
    }

    .signup-form .btn {
      font-size: 16px;
      font-weight: bold;
      background: #3598dc;
      border: none;
      min-width: 140px;
    }

    .signup-form .btn:hover,
    .signup-form .btn:focus {
      background: #2389cd !important;
      outline: none;
    }

    .signup-form a {
      color: #fff;
      text-decoration: underline;
    }

    .signup-form a:hover {
      text-decoration: none;
    }

    .signup-form form a {
      color: #3598dc;
      text-decoration: none;
    }

    .signup-form form a:hover {
      text-decoration: underline;
    }

    .signup-form .hint-text {
      padding-bottom: 15px;
      text-align: center;
    }
  </style>
</head>

<body>
  <div class="signup-form">
    <form action="#" method="post">
      <h2>Registruj se</h2>
      <p>Ispunite ovu formu da biste kreirali račun!</p>
      <hr>
      <div class="form-group">
        <div class="row">
          <div class="col"><input type="text" class="form-control" name="first_name" placeholder="Ime" required="required"></div>
          <div class="col"><input type="text" class="form-control" name="last_name" placeholder="Prezime" required="required"></div>
        </div>
      </div>
      <div class="form-group">
        <input type="email" class="form-control" name="email" placeholder="Email" required="required">
      </div>
      <div class="form-group">
        <input type="password" class="form-control" name="password" placeholder="Lozinka" required="required">
      </div>
      <div class="form-group">
        <input type="password" class="form-control" name="confirm_password" placeholder="Potvrdi lozinku" required="required">
      </div>
      <div class="form-group">
        <label class="form-check-label"><input type="checkbox" required="required"> Prihvatam <a href="#">pravila</a> &amp; <a href="#">uslove korištenja</a></label>
      </div>
      <div class="form-group">
        <button type="submit" class="btn btn-primary btn-lg">Registruj se</button>
      </div>
    </form>
    <div class="hint-text">Već imaš nalog? <a href="#">Prijavi se</a></div>
  </div>
</body>

</html>