core/Templating/templates/edit-screen/default-ui-boxes.twig
{{ contexts.top.render() }}
{% set side2hasAreas = contexts.side2.hasAreas() %}
{% if contexts.side.hasAreas() %}
<div class="kb-context-row grid">
{% if side2hasAreas %}
<div data-kbcolname="Left" class="grid__col grid__col--4-of-12 kb-context-col">
{{ contexts.side2.render() }}
</div>
{% endif %}
<div data-kbcolname="Normal"
class="grid__col {% if side2hasAreas %}grid__col--4-of-12 {% else %} grid__col--6-of-12 {% endif %} kb-context-col">
{{ contexts.normal.render() }}
</div>
<div data-kbcolname="Side"
class="grid__col {% if side2hasAreas %}grid__col--4-of-12 {% else %} grid__col--6-of-12 {% endif %} kb-context-col">
{{ contexts.side.render() }}
</div>
</div>
{% else %}
{{ contexts.normal.render() }}
{% endif %}
{{ contexts.bottom.render() }}