update style of buttons in SideNav

browser/main/SideNav/FolderItem.styl

@@ -12,8 +12,13 @@
   &:hover
     background-color $ui-button--active-backgroundColor
     color $ui-button--active-color
-  .control
+  .control-button
     opacity 1
+    color white
+    &:hover
+      background-color alpha(white, 30%)
+    &:active, &:hover:active
+      background-color alpha(white, 15%)
 
 .label
   position absolute
@@ -29,20 +34,21 @@
   margin-left 5px
 
 .control
-  opacity 0
   position absolute
   top 0
   bottom 0
   right 5px
   width 24px
-  transition opacity 0.15s
 
 .control-button
+  opacity 0
   navButtonColor()
   width 24px
   height 24px
   margin-top 4.5px
   border-radius 5px
+  transition opacity 0.15s
+
 .root--edit
   @extend .root