{% extends "base.html" %}

{% block content %}
  {% url team_create competition.slug as form_action %}
  {% include "competition/includes/horizontal_form.inc.html" %}    
{% endblock %}

{% extends "competition/competition_base.html" %}

{% block content %}
  {% url team_create competition.slug as form_action %}
  {% include "competition/includes/horizontal_form.inc.html" %}    
{% endblock %}

Use competition base for team-create form
Use competition base for team-create form
