fix grid styling

lib/cannery_web/live/invite_live/form_component.html.heex

@@ -1,12 +1,12 @@
 <div>
-  <h2 class="text-center title text-xl text-primary-600">
+  <h2 class="mb-8 text-center title text-xl text-primary-600">
     <%= @title %>
   </h2>
   <.form
     let={f}
     for={@changeset}
     id="invite-form"
-    class="flex flex-col sm:grid sm:grid-cols-3 justify-center items-center space-y-4"
+    class="flex flex-col sm:grid sm:grid-cols-3 sm:gap-4 justify-center items-center"
     phx-target={@myself}
     phx-change="validate"
     phx-submit="save"