django bootstrap form doesn't fit in html page [duplicate]

When i my render my forms.py to my html file does not fit (responsive) entirely on screen

forms.py -

class RegisterUserForm(forms.Form):
      username = forms.CharField(min_length=6, widget=forms.TextInput(attrs={'class': 'form-control'}))
      email = forms.EmailField(widget=forms.EmailInput(attrs={'class': 'form-control'}))
      password = forms.CharField(min_length=8, widget=forms.PasswordInput(attrs={'class': 'form-control'}))
      password2 = forms.CharField(widget=forms.PasswordInput(attrs={'class': 'form-control'}))
      photo = forms.ImageField(required=True)

if i try the site without forms, the page adapts to the screen, but when i add the form "{{form.as_p}}", doesn't work

HTML page -

<div class="panel panel-default">
<div class="panel-heading">
  <h2>User Register</h2>
</div>
<div class="panel-body">
<div class="row">
  <div class="col-md-6 col-sm-offset-3">
    <form role="form" action="" method="post">
      {% csrf_token %}
      {{form.as_p}}
    </form>
  </div>
 </div>
 <button type="submit" name="register" class="btn btn-primary"><span    class="glyphicon glyphicon-log-in"></span> Register</button>
</div>
<div class="panel-footer">
</div>
</div>

I need everything to be adaptive, how do i go about doing that?