fixed the background issue on the tasks tab

app/templates/editor/level/tasks-tab.jade

@@ -1,42 +1,44 @@
-mixin task-row(cid)
-  - var task = view.getTaskByCID(cid)
-  - var taskName = task.get('name');
-  - var isComplete = task.get('complete')
-  tr.task-row(data-task-cid=cid)
-    td.task-check
-      div.checkbox
-        input(type='checkbox', checked=(isComplete || false)).task-input
-    if task.get('curEdit') == true
-      td.edit-cell
-      td.task-name
-        input(type="input", value=taskName)#cur-edit
-    else
-      td.edit-cell
-        span.glyphicon.glyphicon-edit.start-edit
-      td.task-name
-        - var result = view.getTaskURL(taskName)
-        if result !== null
-          // https://github.com/codecombat/codecombat/wiki/Tasks-Tab#<slug goes here>
-          a(href='https://github.com/codecombat/codecombat/wiki/Tasks-Tab#' + result, target='blank')= taskName
+.nano.editor-nano-container
+  .nano-content
+    mixin task-row(cid)
+      - var task = view.getTaskByCID(cid)
+      - var taskName = task.get('name');
+      - var isComplete = task.get('complete')
+      tr.task-row(data-task-cid=cid)
+        td.task-check
+          div.checkbox
+            input(type='checkbox', checked=(isComplete || false)).task-input
+        if task.get('curEdit') == true
+          td.edit-cell
+          td.task-name
+            input(type="input", value=taskName)#cur-edit
         else
-          span= taskName
+          td.edit-cell
+            span.glyphicon.glyphicon-edit.start-edit
+          td.task-name
+            - var result = view.getTaskURL(taskName)
+            if result !== null
+              // https://github.com/codecombat/codecombat/wiki/Tasks-Tab#<slug goes here>
+              a(href='https://github.com/codecombat/codecombat/wiki/Tasks-Tab#' + result, target='blank')= taskName
+            else
+              span= taskName
 
-block
-  table.table.table-striped.table-hover
-    tr
-      th.task-check Complete
-      th.edit-cell Edit
-      th Incomplete Tasks
-    for task in (view.taskArray() || [])
-      if task.get('revert').complete !== true
-        +task-row(task.cid)
-    tr
-      th.task-check
-      th.edit-cell
-      th Completed Tasks
-    for task in (view.taskArray() || [])
-      if task.get('revert').complete === true
-        +task-row(task.cid)
-  button#create-task.btn.btn-primary Add Task
-  if view.missingDefaults().length !== 0
-    button#add-default-tasks.btn.btn-default Add Default Tasks
+    block
+      table.table.table-striped.table-hover
+        tr
+          th.task-check Complete
+          th.edit-cell Edit
+          th Incomplete Tasks
+        for task in (view.taskArray() || [])
+          if task.get('revert').complete !== true
+            +task-row(task.cid)
+        tr
+          th.task-check
+          th.edit-cell
+          th Completed Tasks
+        for task in (view.taskArray() || [])
+          if task.get('revert').complete === true
+            +task-row(task.cid)
+      button#create-task.btn.btn-primary Add Task
+      if view.missingDefaults().length !== 0
+        button#add-default-tasks.btn.btn-default Add Default Tasks