Template source: account/form_signin.html

{% load i18n  %}

<h2 class="box-title">{% trans "Log in" %}</h2>  

<form id="formsignin" signin-href="{% url "accounts:signin" %}" redirect-href="{{ redirect|escapejs }}" class="form-group" onsubmit="return false;" action="#" method="GET">{% csrf_token %}
  <div class="form-group">
    <input type="text" class="form-control" name="username" placeholder="{% trans "Enter username" %}">  
  </div>
  <div class="form-group">
    <input type="password" class="form-control" name="password" placeholder="{% trans "Password" %}">
  </div>  
  
  <div class="notify" style="padding-top: 5px; padding-bottom: 5px; color: red; font-weight: bold">
    <div class="no-such-user template">{% trans "User does not exist." %}</div>
    <div class="wrong-password template">{% trans "Password is wrong! Please try again." %}</div>
    <div class="inactive-user template">{% trans "Your account is inactive! Please, contact site support." %}</div>
    <div class="unknown-error template">{% trans "Unknown error!" %}</div>
  </div>

 <input class="navigation_button btn btn-success" id="next" value="{% trans "Log in" %}" type="submit" /> 
<a class="float-right" href="{% url 'accounts:forgotpassword' %}">{% trans "Forgotten your password?" %}</a> 
</form>