Change CreateFolderInput style from raw color code to variable

Author: sosukesuzuki

browser/main/modals/CreateFolderModal.styl

@@ -29,7 +29,7 @@
   width 490px
   padding 0 5px
   margin 10px 0
-  border 1px solid #C9C9C9 // TODO: use variable.
+  border 1px solid $ui-input--create-folder-modal
   border-radius 2px
   background-color transparent
   outline none
@@ -68,7 +68,7 @@ body[data-theme="dark"]
     color $ui-dark-text-color
 
   .control-folder-input
-    border 1px solid #C9C9C9 // TODO: use variable.
+    border 1px solid $ui-input--create-folder-modal
     color white
 
    .description
@@ -94,7 +94,7 @@ body[data-theme="solarized-dark"]
     color $ui-solarized-dark-text-color
 
   .control-folder-input
-    border 1px solid #C9C9C9 // TODO: use variable.
+    border 1px solid $ui-input--create-folder-modal
     color white
 
    .description

browser/styles/index.styl

@@ -46,6 +46,7 @@ tooltip()
 // UI Input
 $ui-input--focus-borderColor = #369DCD
 $ui-input--disabled-backgroundColor = #DDD
+$ui-input--create-folder-modal = #C9C9C9
 
 // Parts
 $ui-favorite-star-button-color = #FFC216