use 4 spaces instead of 2 spaces. put new line before }

gistfile1.txt

diff --git a/lib/sass/tree/visitors/convert.rb b/lib/sass/tree/visitors/convert.rb
index 5eac1aa..188e195 100644
--- a/lib/sass/tree/visitors/convert.rb
+++ b/lib/sass/tree/visitors/convert.rb
@@ -21,7 +21,7 @@ class Sass::Tree::Visitors::Convert < Sass::Tree::Visitors::Base
   def visit_children(parent)
     @tabs += 1
     return @format == :sass ? "\n" : " {}\n" if parent.children.empty?
-    (@format == :sass ? "\n" : " {\n") + super.join.rstrip + (@format == :sass ? "\n" : " }\n")
+    (@format == :sass ? "\n" : " {\n") + super.join.rstrip + (@format == :sass ? "\n" : "\n#{'    '  * (@tabs-1)}}\n")
   ensure
     @tabs -= 1
   end
@@ -242,7 +242,7 @@ class Sass::Tree::Visitors::Convert < Sass::Tree::Visitors::Base
   end
 
   def tab_str
-    '  ' * @tabs
+    '    ' * @tabs
   end
 
   def dasherize(s)