Added lambda active resolver

Author: syrusakbary

docs/css/playground.styl

@@ -30,11 +30,14 @@
   flex-direction: column
 
   .cm-def
+  .cm-variable + .cm-keyword // lambda
+
     transition all .3s ease-in-out
     background transparent
 
   .activeline
     .cm-def
+    .cm-variable + .cm-keyword // lambda
       $color = #D7D3F1
       // $color = rgba(219, 89, 76, .2)
       background $color