diff --git a/app/views/groups/show.html.haml b/app/views/groups/show.html.haml
--- a/app/views/groups/show.html.haml
+++ b/app/views/groups/show.html.haml
@@ -1,82 +1,92 @@
-.container-fluid
-  .row
-    .col-md-6
-      %h1 Group #{@group.name}
-  .row
-    .col-md-6
-      %b Description:
-      = @group.description
-      %br
-      = link_to 'Edit', edit_group_path(@group), class: 'btn btn-primary'
-  .row
-    .col-md-12
-      %h1 Group details
-  .row
-    .col-md-6
-      .panel.panel-default
-        .panel-heading
-          .panel-title Users in this group
-        .panel-body
-          %ul
-            %li
-              If you want to add several users to a group, it may be easier to just re-import those users in 
-              = link_to 'New list of users', new_list_user_admin_index_path
-              page. You can also use 
-              = link_to 'Bulk Manage User', bulk_manage_user_admin_index_path
-              page.
-          =form_tag add_user_group_path(@group), class: 'form-inline' do
-            .form-group
-              =label_tag :user_id, "User"
+.row.mb-3
+  .col-md-6
+    %h1 Editing Group members and problems
+.row.mb-3
+  .col-md-6
+    %b Name:
+    = @group.name
+.row.mb-3
+  .col-md-6
+    %b Description:
+    = @group.description
+.row.mb-3
+  .col-md-6
+    = link_to 'Edit', edit_group_path(@group), class: 'btn btn-primary'
+.row.mb-3
+  .col-md-12
+    %h1 Group details
+.row
+  .col-md-6
+    .card
+      .card-header
+        Users in this group
+      .card-body
+        %ul
+          %li
+            If you want to add several users to a group, it may be easier to just re-import those users in 
+            = link_to 'New list of users', new_list_user_admin_index_path
+            page. You can also use 
+            = link_to 'Bulk Manage User', bulk_manage_user_admin_index_path
+            page.
+        =form_tag add_user_group_path(@group), class: 'form-inline' do
+          .row
+            .col-auto
+              =label_tag :user_id, "User", class: 'col-form-label'
+            .col-auto
               =select_tag :user_id, options_from_collection_for_select(User.all,'id','login_with_name'), class: 'select2', style: 'width: 25em';
-            =submit_tag "Add",class: 'btn btn-primary'
+            .col-auto
+              =submit_tag "Add",class: 'btn btn-primary'
 
 
-          %table.table.table-hover
-            %thead
-              %tr
-                %th Login
-                %th Full name
-                %th Remark
-                %th= link_to 'Remove All', remove_all_user_group_path(@group), method: :delete, :data => { :confirm => "Remove ALL USERS from group?" }, class: 'btn btn-danger btn-sm'
+        %table.table.table-hover
+          %thead
+            %tr
+              %th Login
+              %th Full name
+              %th Remark
+              %th= link_to 'Remove All', remove_all_user_group_path(@group), method: :delete, :data => { :confirm => "Remove ALL USERS from group?" }, class: 'btn btn-danger btn-sm'
 
-            %tbody
-              - @group.users.each do |user|
-                %tr
-                  %td= user.login
-                  %td= user.full_name
-                  %td= user.remark
-                  %td= link_to 'Remove', remove_user_group_path(@group,user), :method => :delete, :data => { :confirm => "Remove #{user.full_name}?" }, class: 'btn btn-danger btn-sm'
-    .col-md-6
-      .panel.panel-default
-        .panel-heading
-          .panel-title Problems
-        .panel-body
-          %ul
-            %li
-              If you want to add several problem to a group, it may be easier to bulk manage them in the
-              = link_to 'Bulk Manage Problems', manage_problems_path
-              page
-          =form_tag add_problem_group_path(@group), class: 'form-inline' do
-            .form-group
-              =label_tag :problem_id, "Problem"
+          %tbody
+            - @group.users.each do |user|
+              %tr
+                %td= user.login
+                %td= user.full_name
+                %td= user.remark
+                %td= link_to 'Remove', remove_user_group_path(@group,user), :method => :delete, :data => { :confirm => "Remove #{user.full_name}?" }, class: 'btn btn-danger btn-sm'
+  .col-md-6
+    .card
+      .card-header
+        Problems
+      .card-body
+        %ul
+          %li
+            If you want to add several problem to a group, it may be easier to bulk manage them in the
+            = link_to 'Bulk Manage Problems', manage_problems_path
+            page
+        =form_tag add_problem_group_path(@group) do
+          .row
+            .col-auto
+              =label_tag :problem_id, "Problem",class: 'col-form-label'
+            .col-auto
               =select_tag :problem_id, options_from_collection_for_select(Problem.all,'id','long_name'), class: 'select2', style: 'width: 25em';
-            =submit_tag "Add",class: 'btn btn-primary'
+            .col-auto
+              =submit_tag "Add",class: 'btn btn-primary'
 
 
-          %table.table.table-hover
-            %thead
-              %tr
-                %th name
-                %th Full name
-                %th Full score
-                %th= link_to 'Remove All', remove_all_problem_group_path(@group), method: :delete, :data => { :confirm => "Remove ALL PROBLEMS from group?" }, class: 'btn btn-danger btn-sm'
+        %table.table.table-hover
+          %thead
+            %tr
+              %th name
+              %th Full name
+              %th Full score
+              %th= link_to 'Remove All', remove_all_problem_group_path(@group), method: :delete, :data => { :confirm => "Remove ALL PROBLEMS from group?" }, class: 'btn btn-danger btn-sm'
 
-            %tbody
-              - @group.problems.each do |problem|
-                %tr
-                  %td= problem.name
-                  %td= problem.full_name
-                  %td= problem.full_score
-                  %td= link_to 'Remove', remove_problem_group_path(@group,problem), :method => :delete, :data => { :confirm => "Remove #{problem.full_name}?" }, class: 'btn btn-danger btn-sm'
+          %tbody
+            - @group.problems.each do |problem|
+              %tr
+                %td= problem.name
+                %td= problem.full_name
+                %td= problem.full_score
+                %td= link_to 'Remove', remove_problem_group_path(@group,problem), :method => :delete, :data => { :confirm => "Remove #{problem.full_name}?" }, class: 'btn btn-danger btn-sm'