Make form pages 2/3 width

app/views/form/page.html.erb

@@ -3,7 +3,8 @@
 <% end %>
 
 <%= turbo_frame_tag "case_log_form", target: "_top" do %>
-
+  <div class="govuk-grid-row">
+    <div class="govuk-grid-column-two-thirds">
       <% if page_info["header"].present? %>
         <h1 class="govuk-heading-xl">
           <%= page_info["header"] %>
@@ -24,4 +25,6 @@
         <%= f.hidden_field :page, value: page_key %>
         <%= f.govuk_submit "Save and continue"  %>
       <% end %>
+    </div>
+  </div>
 <% end %>