{% extends 'AppMainBundle::layout.html.twig' %}

{% block main %}
    <div class="container">
        <div class="row">
            <div class="col-md-8 col-md-offset-2">
                <div class="submit">
                    <h2>Add your own plays!</h2>
                    {{ form_start(form) }}
                        {{ form_row(form.title) }}
                        {{ form_row(form.author) }}
                        {{ form_row(form.url) }}
                    {{ form_end(form) }}
                </submit>
            </div>
        </div>
    </div>
{% endblock %}

{% extends 'AppMainBundle::layout.html.twig' %}

{% block main %}
    <div class="container">
        <div class="row">
            <div class="col-md-6 col-md-offset-3">
                <div class="submit">
                    <h2>Add your own plays!</h2>
                    {{ form_start(form) }}
                        {{ form_row(form.title) }}
                        {{ form_row(form.author) }}
                        {{ form_row(form.url) }}
                    {{ form_end(form) }}
                </submit>
            </div>
        </div>
    </div>
{% endblock %}

Change the submit form size
Change the submit form size
