Add unit tests for LoginButton component with comprehensive coverage

frontend/vue-app/src/components/profile/UserProfile.vue

@@ -1,5 +1,5 @@
 <template>
-  <div class="edit-view">
+  <div class="view">
     <EntityEditForm
       entityLabel="User Profile"
       :fields="fields"
@@ -54,7 +54,6 @@ import { useRouter } from 'vue-router'
 import EntityEditForm from '../shared/EntityEditForm.vue'
 import ModalDialog from '../shared/ModalDialog.vue'
 import '@/assets/styles.css'
-import '@/assets/colors.css'
 
 const router = useRouter()
 const loading = ref(false)
@@ -220,6 +219,14 @@ function goToChangeParentPin() {
 </script>
 
 <style scoped>
+.view {
+  max-width: 400px;
+  margin: 0 auto;
+  background: var(--form-bg);
+  border-radius: 12px;
+  box-shadow: 0 4px 24px var(--form-shadow);
+  padding: 2rem 2.2rem 1.5rem 2.2rem;
+}
 /* ...existing styles... */
 .email-actions {
   display: flex;
@@ -231,10 +238,6 @@ function goToChangeParentPin() {
   margin-top: 0.1rem;
 }
 
-.btn-link-space {
-  margin-top: 1rem;
-  margin-bottom: 1rem;
-}
 .success-message {
   color: var(--success, #16a34a);
   font-size: 1rem;