Update global.styl

Author: aprouja1

src/devtools/style/global.styl

@@ -73,13 +73,13 @@ $arrow-color = $vue-ui-color-dark
 
 .vue-ui-dark-mode .arrow
   &.up
-    border-bottom 6px solid $white
+    border-bottom-color $white
   &.down
-    border-top 6px solid $white
+    border-top-color $white
   &.right
-    border-left 6px solid $white
+    border-left-color $white
   &.left
-    border-right 6px solid $white
+    border-right-color $white
 
 .notice
   display flex