visgraph: give more space to graph in twig content

src/Bundle/ChillPersonBundle/Resources/views/Household/relationship.html.twig

@@ -2,12 +2,24 @@
 
 {% block title 'household.Relationship'|trans %}
 
-{% block content %}
-    <h1>{{ block('title') }}</h1>
+{#
+     Give more space to graph:
+     * use parent twig block (layout_wvm_content)
+     * hide title (d-none)
+     * apply negative margin-top
+#}
+{% block layout_wvm_content %}
+<div class="row justify-content-center">
+
+    <div class="col-md-10 col-xxl d-none">
+        <h1>{{ block('title') }}</h1>
+    </div>
 
     <div id="relationship-graph"
+        style="margin-top: -3rem"
         data-persons="{{ persons|e('html_attr') }}">
     </div>
+</div>
 {% endblock %}
 
 {% block block_post_menu %}