No sight of all forms in formular (HTML/PHP)

Hi people around the world
I got a question concerning displaying a form:
I got here a simple form

 <form method="post" action="" enctype="multipart/form-data">
                 <div class="uk-margin">

        <input class="uk-input" type="text" placeholder="First Name" name="first" required>
    </div>

     <div class="uk-margin">

        <input class="uk-input" type="text" placeholder="Last Name" name="last" required>
    </div>

     <div class="uk-margin">

        <input class="uk-input" type="text" placeholder="Phone Number" name="phone" required>
    </div>

    <div class="uk-margin">

        <input class="uk-input" type="text" placeholder="Age" name="age" required>
    </div>



        <div class="uk-margin">
        Gender<select class="uk-select" name="gender" required>
            <option selected>Male</option>
            <option>Female</option>
        </select>
    </div>

     <div class="uk-margin">
       Blood Group <select class="uk-select" name="blood" required>
             <option  selected >A+</option>
  <option >A-</option>
  <option >B+</option>
  <option >B-</option>
  <option >O+</option>
  <option >O-</option>
  <option>AB+</option>
  <option >AB-</option>
        </select>
    </div>

Now on the browser I cant see all forms, see.

Why does this got such a behaviour?

Kind regards ; https://i.stack.imgur.com/TwYJM.png